I was going to criticize & point out how usb-c chargers at and over 100W are just so small, but there's a photo comparing it to an iphone & ok, it looks adequately impressively dense! (I have a >2 year old 100W charger that is 66x64x30mm, this 250W unit is 170x50x25)
It's been such a great synergy. Energy efficiency has been a concern already yes, but I really view usb-c chargers as pushing the consumerization & massification & development of this technology to the superb, common, un-exotic levels it's come down to. We just got tired of doing less good, actively explored trying to use a somewhat harder to drive switching semiconductor, & have reaped great rewards. Miniaturization mandated optimization & we all win. I really think the interchangable-parts/modularity & resulting competition that usb-c begot started this ball rolling.
(Hoping USB-PD, with it's bump from 20 up to 48V, once again proves another huge win!)
I'd also point to Google's Little Box Challenge[1] as an interesting data-point of yore.
Little Box Challenge went the other direction: instead of taking AC and producing DC power, it was an inverter that took DC power and produced AC output. It had to output 2kW and be smaller than 655 cubic centimeters (cc's). The winning Red Electrical Devil's team got 3x more dense than this[2]! 240 cc's! While inverting 2kW of juice. Second place was 340ccs.
I don't know whether we'd argue this DC->AC is harder/easier than an ATX supply (AC->DC) (probably not?) but this was quite an impressive competition, almost a decade ago, that resulted in probably some of the most power-dense, highest-efficiency power conversions that humanity has ever gotten up to. For compare, this 250W unit is 212cc's. 8x less power conversion, 88% the size.
The Little Box Challenge designs were published, so there's a ton of great reading. Alas, Google frakking let the damned site bitrot off the net?! Sooo, head to archive.org[3] to read the team's writeups. From the winning CET Red Electric Devils writeup:
> GaN transistors have many very interesting electrical characteristics (low Rds_on, low Qgate and Cds, ultra low Qrr); these create technological advantages over current MOSFET and IGBT devices (small size and low production costs). Unfortunately, they also have serious drawbacks due to their very fast switching characteristics: they are challenging to drive and require sensitive electromagnetic noise management. Another pitfall is the high voltage drop due to the reverse current when the GaN is turned off. The solution selected to overcome these difficulties is to control all the GaN transistors using soft switching for the entire operation range.
I'm doing an EV conversion, and have trouble wrapping my head around the idea that a motor controller that weighs about ten pounds or so and isn't much bigger than a loaf of bread can handle about 100 kilowatts of power, converting DC at around 140-180 volts from the battery to 3-phase AC. And that's a relatively low-end inverter.
the answer is liquid cooling. these Little Box and ATX power supplies have to rely on passive cooling (radiative, conductive, and convective) which is generally proportional to surface area == physical size ^ 3. if you halve the size, then, you lose 87.5% of the surface area! that's why these things can't shrink as much. but ultimately the silicon involved is miniscule.
Technically my motor controller can be passively cooled too, it's just not recommended. (It automatically goes into a low-power "limp" mode rather than burn itself out.)
I'm not sure how much power it can handle continuously in a pure passive-cooling mode.
It would also be worth noting that a typical EV doesn't have to run at anything close to 100% load for extended periods of time.
What sort of power an electric drivetrain can handle for a burst of acceleration lasting a few seconds versus what that same drivetrain can handle as a continuous load are two very different things.
The same even applies with combustion powered cars too, if you look at the pickup truck market you'll see massive power numbers on every manufacturer's diesel pickups. If you look at their chassis-cab commercial trucks those same diesel engines are often derated by 30-50% compared to the pickups even while being equipped with larger cooling systems. That's because the commercial variants are rated to perform to spec all day every day where the pickup version just needs to put a grin on the owner's face when they floor it off the line and then occasionally tow a boat or something.
> I don't know whether we'd argue this DC->AC is harder/easier than an ATX supply (AC->DC)
The little box challenge was significantly harder, primarily due to the ripple requirements on the DC side. This is not an issue in the same sense in the AC->DC case, because you don't have that problem there (you have other ripple considerations that might look similar, but are not (PFC and ripple on the output)). Usually you would require a lot of capacitance to solve the ripple issue for DC->AC and the winning team had a very interesting way of solving it without the use of very large capacitors.
> I don't know whether we'd argue this DC->AC is harder/easier than an ATX supply (AC->DC) (probably not?) but this was quite an impressive competition, almost a decade ago, that resulted in probably some of the most power-dense, highest-efficiency power conversions that humanity has ever gotten up to.
The LBC was misshapen because they had an odd requirement: Be single-phase. A three-phase inverter (or rectifier) naturally has low DC ripple and is both more compact and more efficient than a single-phase inverter at all power levels. All of the winning solutions had extra energy storage elements which added inefficiency and bulk which a three-phase inverter would not have needed.
With that in mind, the LBC was a little silly. A three-phase machine at the same power level would have been much smaller than any of the "winning" designs.
A high-efficiency ATX power supply has additional requirements that the LBC didn't need to meet: Isolation. This implies the use of a transformer to protect the low-voltage DC side from the AC side. They typically accomplish this by rectifing AC, using a transformer-isolated unidirectionally optimized DC/DC supply to 12V, and then provide a handful of lower-power DC/DC converters to derive the other voltage levels used by ATX. A modern unisolated DC->AC machine is effectively symmetric in its power flow, and also functions as an AC->DC machine.
One of the things I only recently learned is modern power supply’s aren’t using the transformer to knock down “raw mains” 60hz AC. Modern switch mode PSU’s in-fact rectify the AC to DC and then chop it up at a much higher frequency.
By using a higher frequency, the transformer can be much smaller and more efficient. If they were doing mains 60hz AC the transformer would be substantially larger.
I forget if they also step the supply side DC voltage up too…
> I forget if they also step the supply side DC voltage up too…
They do, but they don't have to. The front-end rectifier boosts the voltage up to 400-450 VDC. This way, most of the components can be optimized for a single world-wide compatible machine that is capable of rectifying 230VAC.
In principle, you could squeeze out a bit of efficiency (or cost) by producing a North American market machine that was optimized for 120V and a separate machine optimized for 208/230V. In practice, supply chain simplification reduces overall per-unit costs, so just about everything is designed as a single machine for world-wide markets. Only the plugs change. For ATX, only the cord shipping in the box changes.
The interesting thing about gallium nitride is its use in blue LEDs (light-emitting diodes), which was discovered in 1972 and perfected in 1993, resulting in a Nobel prize.
It's effectively process technology improvements that allow gallium nitride devices to become less defect prone.
It's been known for some time that GaN has a superior electron mobility number (which, effectively means you can get a better/smaller/lower impedance/faster switching device depending on which tradeoff you want). Problem is, getting reasonably good process control has been challenging. It appears some folks in the industry have been overcoming that challenge, therefore we're seeing the results of that.
I've found high-wattage USB-C chargers to have very poor reliability. All the 18-W chargers I've owned have lasted multiple years, but the compact 90-W+ chargers have a lifespan measured in months.
Of course, they all purport to offer a warranty, but if you try to claim, they will not honor it. They will claim it's because you bought from Amazon and they don't warrant Amazon purchases (despite this being their main retail outlet, and the fact that they advertised the warranty IN the Amazon sales materials). Or something similar.
I have a ravpower, a hyper, and just bought the new ugreen. The ugreen is too new to judge, but the others have ran for over two years, and a good amount of that time has been outdoors in the sun.
I constantly expect failures. This seems like an absurd task I'm putting them up to. But they are all still alive & doing the job.
I've had a kill-a-watt so I can see their power consumption. A large amount of their life is spent ~60 watts, but there's definitely hours on end & heavy usage days, where they go up to or stay at 90+.
My Ravpower device died within 8 months, and they refused to honor the warranty, giving as the reason that the purchaser of record was Amazon LLC, not Ravpower. Even though they advertised a warranty on their Amazon page, which was the main way they sold the devices.
So this is a very frequently repeated misconception about what the EU law actually says.
Yes, there is an EU law that says retailers are responsible for 2 years(6 in a some cases) for any item they sold......but only to rectify any manufacturing defects. The law additionally states that any defect found in the first 6 months is presumed to be a manufacturing issue, anything after the first 6 months it's the responsibility of the customer to prove that the product has failed due to a manufacturing problem. I'm sure you can appreciate that this can be very hard to do.
It's not a "warranty" in the sense that most people mean warranty. If your laptop fails 18 months after purchase, the retailer only has to fix it if you can prove that it failed due to a manufacturing defect. It's different to manufactuer's warranty, which usually covers any defect no matter the reason.
And yes, there is also the law that states that products should last a "reasonable" amount of time - but what is reasonable is not a strict definition, and again, unfortunately sometimes has to be argued in small claims court. It's not so straigtforward.
However, in practice most good retailers do not make a big deal out of the burden of proof as long as there is no visible damage that could cause the issues.
I have used warranty frequently after 6 months and never had to prove it is a manufacturing defect. Of course, if you buy at some shady webstore or known-bad retailer, you might have more issues.
These are not EU laws, they are EU directives directing the member countries to implement laws. But these laws are not all the same, for instance in how much effort a customer has to make to ‘prove’ that a device failed due to a manufacturing defect.
Does Amazon not honour the warrenty in that case? I've never had to deal with a similar situation but I kind of figured that Amazon would do something if the page advertised a warranty and the company refuses to honour it.
I have never been able to get Amazon to honor a warranty when the manufacturer refused, even though the law in my country clearly says the retailer is responsible in the first place. In fact the button to return a product disappears from the order after a couple months, and they don't even have a category in their support system for this.
Apple cares about its brand. Chinese no name vendors don't at all, it's horrifying what plain illegal corner-cutting they often engage in. But that's of course what they're rewarded for.
In fact, if you're in a bind and need a USB C charger that will work reliably, you may want to pay the cost to get a genuine Apple one. (I won't order Apple chargers from Amazon; I get them direct from Apple or a real retailer because I don't trust the co-mingling).
I agree - I wonder why Chinese junk that basically barely works and not for long even then has managed to establish such a strong foothold on the retail market (particularly Amazon).
I had the same experience - moreover my charger had multiple ports, but as soon as you plugged more than one thing into it, the wattage would drop drastically. my 100W charger would do 30W on port 1 and 10W on port 2. And that was the optimal case - more often than not, using more than one port would make devices randomly disconnect.
I just had a 4-port USB brick burst into flame. It certainly would have burned down the house if I had not happened to be in the room. It had sat untouched for an hour before the event.
Better than the brand is the picture of the device (before fire, hopefully) as all the yumcha brands off of Alibaba will usually keep the exact same physical characteristics.
It's cheap and there's little responsibility for selling crap. Amazon is the only site I'm aware of where you can actually somewhat judge the quality of a product through reviews, and those too are often dodgy as hell. Otherwise it's all just the same fake pictures and outright lies about specs. And nobody cares because it's cheap.
Companies selling under brands want a premium for them (Anker, Aukey) and "no name brands" you can actually put a little confidence into (Ugreen, Blitzwolf) are, for some reason, rare.
That isn't so surprising nor uncommon even among high-end chargers. Many multiple-port chargers can only generate one voltage other than 5V.
So, you charge your laptop at 100W means 20V*5A, then connect a phone that can only negotiate to 9V. Now your laptop can, at best, only get 45W. But laptop and phone might also have to share the same 5A, meaning something close to what you described. (or, your laptop might not support 9V ... in which case I'd guess one of the devices would disconnect?)
You might be better off using a USB-A port if the charger has one, then your laptop could perhaps remain at ~100W and your phone might still get ~10W. (Assuming charger and phone doesn't also have quickcharge which might complicate it further). Or, perhaps charge your phone via your laptop (yes, negates the point of a multiple-port charger, but if you are in hurry - otherwise, slow charging is preferably anyway)
A good review will test this, and a good product page will specify this (but if your are not looking/thinking about it it is easy to miss).
I have had a couple of pretty cheap high wattage USB bricks for years (5-6 or so at this point) and none of them have died on me so far. Props to Ugreen, I guess!
I think you might be unlucky or buying low-quality models. I have a 100W Minix NEO P2 that was one of the first GaN chargers available near me and it's still going strong 2 years later.
I also have a 60W Satechi travel charger that's been powered-on 24/7 for 3 years now without the slightest hint of a problem. It's even been buried under cushions for hours at a time.
The only charger I've had actually die was a Hama-branded device. Hama is the cheapest possible Chinese junk the brand can find.
I use it to power my CPU+mobo but I also have a couple of server PSUs further away to power my 3090 over several pairs of THNN. It’s far from a SFF build, but it can be totally silent.
The difference is that this unit does the AC-DC conversion inside itself, whereas your DC-DC power supply relies on an external AC-DC brick that is likely the same size as this entire self contained unit, if not larger.
To be a fair comparison would need to include the AC-DC power supply that you keep outside to power that thing... it's double the size once you account for that.
More like 3x. My Emerson 7001484-J000 PSUs go full depth into a server chassis. But that’s a sunk cost since it’s much easier to build a 12VDC UPS instead of a 120/240VAC UPS
I my complaint that they are calling this atx, when the only thing remotely ATX about it is being designed to work with the atx motherboard power connector.
This in no way meets the atx form factor for power supplies, neither the original, nor the 12V version. Like I could forgive it if it failed to be a rectangular prism in favor of having more open space, as long as it had a frame with proper mounting points.
And I could also forgive it if they went with the rectangle, but far shorter than the official 140mm depth (that has always been mandatory per intel specs), given that the market already accommodates non-conforming lengths, and this could be made to not require the bottom of case mounting holes, allowing for absurdly short lengths.
But the photos show none of that, and just a fully custom form factor, without any apparent mounting mechanism.
The form factor and mounting design of the power supply are not parts of the ATX spec. The pin layout & shape, voltages, signaling, etc are what are specified.
This is an ATX power supply. It is just designed for very small cases that would never be able to accommodate the existing standard configurations.
>The form factor and mounting design of the power supply are not parts of the ATX spec. The pin layout & shape, voltages, signaling, etc are what are specified.
Did you just pull this out of nowhere?
Look at ATX Specification v. 2.01 section 4.1, page 18-20. It specifies the "required overall dimensions and general form factor of an ATX power supply," with or without special airflow ducting (emphasis in original).
The linked PSU in the OP clearly does not meet this form factor.
> (Hoping USB-PD, with it's bump from 20 up to 48V, once again proves another huge win!)
Can someone explain to me why 48V? Is there something special with 48V or beyond? The reason I ask is because some cars now have electric turbos and the manufacturer had to switch to a 48V system. Just curious what the benefits of higher voltage is and if 48 is somehow special.
Power is the product of current and voltage. To transfer much power at a low voltage requires a large current. Supporting a large current without getting hot and melting requires large-diameter wire. Other components may also be bulky or expensive if they have high current-handling requirements.
I seem to recall that somewhere around 50 volts is a magic number from a safety/regulatory perspective. It might also have something to do with semiconductor breakdown voltage, but maybe I'm out of date on that.
My understanding is that 50V is the established threshold above which safety to humans starts to be a factor. So, applications that want high powers, without the penalty of large wires nor the penalty of the safety requirements of an HV system, converge to 48.
> the established threshold above which safety to humans starts to be a factor
Specifically, 50 volts is approximately the threshold above which electricity can pass through the skin and shock you. Lower voltages will only shock humans if they have a way to bypass some of the skin, like wounds or tight-fitting metal jewelry. Otherwise, the resistance of skin is high enough to prevent the flow of electricity. That's why you can touch both terminals of a 12V car battery at the same time and almost certainly not be shocked.
At 48v you can use much smaller gauge wire than at 12v. Which means lower cost, less weight and a smaller footprint for your wire harnesses.
One of the things that can “get you” with these higher voltage systems is you can’t use them to jumpstart the present majority of cars. While I’ve yet to actually see a higher voltage car, I would hope they’d put warnings by the battery to remind the user that “hey, don’t try to jumpstart your friends car with this battery!”
So about quarter the size of a standard SFX PSU, which is pretty cool. But also about a quarter the power the 'biggest' ones can provide.
I can see this being really good for (for instance) boxes like my fileserver which has a 65W TDP i3 in it and a bunch of SSDs, or compact media boxes that just have a processor and iGPU.
Unfortunately the way things are going in the world of PCs, you aren't going to power much of a modern dGPU from that.
The cables are bigger than the PSU. Has anyone ever experimented with putting edge connectors on a motherboard PCB for power? And edge connector for PCI and memory and m.2? In this way you could build out a very flat PC with commodity parts, since all the components would be parallel to each other and the motherboard.
You should look at CRPS form factor power supplies, they have the edge connector you are referring to. ATX12VO also addresses the large legacy ATX connector.
Aren't OEMs already able to do pretty much what they want?
I have a desktop HP that has a standard-sized PSU but has a weird connector that only plugs into the motherboard. The drives are powered from a separate connector that also plugs into the motherboard. And the PSU - MB connector is much smaller than standard ATX.
HP can control the full stack. MB and PSU at the same time. But smaller OEMs might want to not have to manufacture their own totally custom components. So it makes sense for them to standardize. If not for interchangeablity then to ensure you can sell your custom parts to other OEMs.
I know we don't need 5v for spinning drives anymore, but what voltage does the CPU want to see? If it's not 12V aren't we just moving the voltage drop equipment onto the motherboard?
CPUs are around 1-1.2v. However, they can occasionally pull 100-200+W. Moving 200W at 1V means 200A. Resistive losses scale proportional to amperage at constant voltage, and inversely proportional to voltage at constant power. 200A needs a LOT of copper to not get blistering hot, the amount you would find in all the traces connecting a CPU to the VRMs on the motherboard, probably around 4 ounces just to carry the power a few inches. 200W at 12V is 16.7A, which can be shuttled much longer distances with less material at the same efficiency, in the ~foot long cable between the PSU and motherboard. Additionally, pluggable connectors are high resistance spots in the circuit unless they make very good contact, and susceptible to overheat and melt when carrying too much current.
The VRMs for the CPU have already been on the motherboard for a very long time, maybe always? CPUs operate at very low voltages with very high amps. For a lot of reasons, it makes sense to keep that as close to the processor as possible.
You can get 90 degree adapters for the motherboard power connector and PCI, and low profile ram. the issue then is getting a low profile heatsink for the CPU. There are waterblocks but not many with edge ports.
There are also boards like this that have the RAM mounted flat, a lower profile set of ports on the back, and take in 19v DC: https://www.asrockind.com/en-gb/IMB-193
>the issue then is getting a low profile heatsink for the CPU
You'd have to make something custom, but I think it would be much simpler than typical heat sinks. With air cooling, the vertical placement would be ideal, since convection will tend to suck cool air from the bottom and release it on the top. (I think the iMac does/did this). Even for water cooling, it would be simpler with far fewer turns in the pipe. Plus, I just like the idea of laying everything out flat instead of the weird 3-D origami that is modern PC design.
I hate to be the one but a) this means fixing these psu's are going to be even harder now and b) at some point people are going to have to worry about energy intensity (W/m^2) exceeding values where the devices themselves will melt. That said, interesting tech. It feels like a lot of new tech news these days is just furthering gimmicks (adding "blockchain" to this or ML applied to something that didn't need it) but this is actually cool and could open a host of new applications.
How frequent are the failures? It costs a lot less than $20 to repair a broken power supply, but if you break less than $5000 worth of power supplies per month you're not breaking even on the technician not even counting the management overhead.
I don't think small cost savings like that are going to be implemented simply because it makes the operation more complex without landing any manager a big fat bonus.
Unless I'm grossly underestimating the failure rate of those supplies?
So you're saying in your DC enough of them break that they could feed a technician? Say the technician would have an 80% success rate and he saves $100 bucks per repair, there would need to be 63 failures per month for there to be 0 cost savings. What's the minimum cost savings for it to be worth a managers time? Maybe double it again so 125 failures per month?
I wonder if the vendor would void the warranty and that would have any consequences.
Actually I did a study on this (I'm a PM for a small server company) about a year ago with data scraped from a popular US based online vendor.
For PSUs >1000 watts, I found that server supplies are cheaper both on a relative (more watts / dollar) and absolute cost basis than ATX form factor supplies.
Aren't the >1k watt ATX power supplies usually the "gamer edition" ones with huge markups? They cost a lot because they are a small niche--very few PCs need power supplies that big, and the ones that do are running multiple wildly expensive GPUs so budget is clearly not a concern.
There's probably more legitimate demand on the commercial side for >1kw PSUs so they can enjoy larger economies of scale.
I don't know if you're trolling but, probably it's all about support contracts and liability.
- If your hardware hasn't reached EOL, it's probably under a warranty or support contract. So you just let your provider swap/fix it.
- If you tinker with anything and there's a problem with the rest of the hardware, they'll probably won't honor the warranty or support contract, or you could have problems with your insurance.
If it were a home user fixing a PSU... that's a different thing.
> It certainly seems like if it's worthwhile for anyone to do with unspecialized labor, then it would certainly be worth doing for a specialist
'Anyone' could be a penniless student and his time costs little, specialist may charge $40 per hour.
Also even ideal free market has cost of transaction, discoveravility, etc.
Hospitals have repair technicians, but why would you need one spesifically focusing on power supplies - he does not need different training or equipment
If you have a hundred identical power supplies that need fixing, they probably all have the same fault, and the fix will probably be 3 minutes labour + 20 cents in parts after the first one. That's totally worth doing.
Clearly the 0.01% of people who have even opened a PSU are going to chime in and say it’s necessary.
I’ve torn mine apart and replaced fans in them and such but I’ve never had to resolder any parts onto them. If a PSU dies - it tended to do it violently and was so cheap that it wasn’t worth doing it. All the name brand ones I’ve had never had any issues and same for the dozens of other people I knew. (Or computers I worked on or built or sold to others… or when I did IT and saw literally thousands of computers…)
I fixed mine once. I lived in a university town, which caused the small unusual circumstance that no local store had a 700W power supply in stock, but there was a electronic parts store that had the capacitor I needed to replace.
Besides the capacitor only costing 10 cents and a new one around a hundred bucks the advantage for me was that I had fixed the whole thing within na hour or two including diagnosing the issue and the bike ride to the shop.
I was back on my PC that same night, and 5 years later that same PSU now well over ten years old is still going strong.
A few minutes is more than enough under normal conditions. Modern electronics all have bleed resistors that drain any dangerous capacitors when the device is off. In microwave capacitors the bleed resistor is built into the metal can of the capacitor itself. You should always assume capacitors are charged unless proven otherwise. Just grab a screwdriver with an insulated handle and short out the capacitor before assuming it's safe.
How many people fix their psu vs eWaste when they stop working, which is usually 5+ years after they were made, unless they were made with unusually poor components or design?
I don't necessarily need a smaller power supply, but options are nice.
Most boards have a couple components that are on the weak side and fail, usually a capacitor. Any electronics shop can fix it for at most $20, or you can do it yourself for the cost of a 20 cent component though usually not worth the time. Beats paying $100 for a new PSU.
Fixing PSU's has never been hard. And actually looking at the board it looks like this is even easier to take a part and work on than the PSU I have repaired.
$145 is pretty steep, and I'd like to see the Vpp (also called ripple) before considering this. I currently use picoPSU (ASIN B005TWE5E6), 50W and 80W versions to power 7th and 8th gen atoms and celerons. I use a "UPS" style 12VDC PSU connected to a fairly large sealed lead acid battery - about 4x the volume of a standard UPS battery. As far as my measurements go with the induced noise from the PSU for radio reception work, it seems to work pretty good. I've looked at using SBCs instead, but you're never really going to get away from buck/boost on boards, since some things need 3.3 or less volts (memory, etc). The picoPSU also have survived for years up in elevator attics with all of the machinery and dust. never had an outage caused by the picoPSU or the attached 12V UPS stuff.
I wonder if it is possible to run more than one board off the same PSU. I know you can run a board off multiple PSUs, but is the inverse true? If i ever get a new batch of these 25W TDP computers racked, having 2 of these connected to two UPS and 6 computers might be cool. It's just the ATX connector that needs population, i use NVME whenever possible, no GPU, no cards, just USB and ethernet onboard.
> I wonder if it is possible to run more than one board off the same PSU.
Absolutely. There's something I can't remember about signal lines that need to be set up, but yet, people have been running multiple computers off as single supply for a long long long time now.
Also worth warning people ahead of time, it's hard to predict what kind of specific power consumption a motherboard will have. There's so many power rails going in. 3.3V, 5V, 12V, -3.3V... Making sure that each rail is adequately rated for additional motherboards can be a challenge. Ideally one would test each supply line, one by one, to try & figure things out, & compare against rated specs of the power supply.
Intel's been pushing a new spec called ATX12VO, short for 12-volts-only, which does away with all the other rails & has the motherboard expect 12v. This would make it much easier to understand what power consumption is. I do seem to recall some of the new ATX specs (3.0?) also kind of expect power-consumers to declare how much power they expect to use, as a safety/planning feature, which could complicate this one easy-to-do hack (unless there's some way for the additional motherboard/motherboards to also declare their power draw). This might only be ATX3.0's new 12VHPWR connector, which works alongside PCIe 5.0-- not sure if it also impacts motherboards or not.
These days the 3.3v rail and -3.3v rail are practically vestigial (iirc the major consumer on those rails was floppy disk drives...) and 5V is mostly used to drive SSDs and USB devices. Almost everything runs off 12V these days - which is the whole point behind the 12VO standard, just make everything use 12V and step it down at the point-of-consumption for the handful of things that still need something else.
So basically I wouldn't worry about motherboard compatibility due to 5v, 3.3v, and -3.3v rails - there just isn't much of anything still being done on those rails, and the things that do use it pretty much are the same across motherboards (because they're things that are plugged into the motherboard, not the motherboard itself).
> and 5V is mostly used to drive SSDs and USB devices.
The most important 5V rail is 5VSB - it powers wake-on-LAN and on some systems wake-via-bluetooth. The interesting question is, is it more efficient to always let 12V->5V regulators run for 5VSB or to use an extremely small separate regulator?
To be fair, something is stepping it down from AC, and many modern PSUs step everything down from a common DC rail using DC-DC conversion (i.e, 12V, 5V, 3.3V, etc are all generated from a source DC voltage). Then things like the CPU and GPU have long moved off of the 3.3V rails to harness the 12V rail for DC-DC conversion in various VRM stages, down to <<2V.
My main appreciation for ATX12VO (12 volts only) is the MB can choose to right size the 5V and 3.3V rails appropriately. M.2 slots are driven from 3.3V only (even if M.2 devices step it up or down for their specific uses). A board with 4 M.2 slots will have a different potential 3.3V power demand than a board with only 2 slots. Typically, a decent board will have 1 M.2 2230 A or E slot for WiFi, and 1-2 M.2 2280/22110 M (and rarely B) slots for M.2 storage. PCIe x16 lanes will have 9W of 3.3V, as part of their 75W total power (the remaining 66W is 12V).
As noted earlier, 5V is heavily I/O driven. A board with 15 USB ports can expect to need more 5V than a stingy board with only 8 (both are accounting for front I/O headers).
I'd rather the MB have to right-size the 3.3V and 5V rails, than forcing every PSU to include copious amounts of 3.3 and 5 just to cover every edge case.
Sure, it's a tiny bit of potential efficiency. It's also passing a bit of cost from the PSU to the board itself. Sadly, it does seem ATX12VO's main impact will be lost. OEMs are going to continue with their custom PSUs with unique connectors and the DIY vendor + consumer market has largely turned their backs to this.
> The interesting question is, is it more efficient to always let 12V->5V regulators run for 5VSB or to use an extremely small separate regulator?
To complicate this further, full system power-off is not the only time you want to do wake-on-lan... if you want to wake from system sleep then you have to be running the 12V rail anyway, because that 12V rail drives the VRMs which drive Vcore and Vmem. No 12V rail means you lose your memory and CPU state...
As such I don't think you can really frame this as "having a separate 5V regulator with the 12v rail turned off", or at least that use-case must exist in addition to the deep-sleep use-case, it cannot supplant it entirely.
Anyway though, power-supply 5V rails are usually much much larger than they need to be, and that has higher loss inside a transformer. Even if you make that a solid-state thing inside the transformer, moving power at 5V is less efficient than moving it at 12V and stepping it down at the point-of-consumption. So actually the answer is probably that it's more efficient to always run a step-down regulator.
Can you show me what you mean by the UPS style PSU? That setup sounds like it would be great for keeping my mini server up during power outages (Xeon-D also running off of a picoPSU).
sure, ASIN B00EAIG17E "DROK 110V 220V UPS Battery Backup Uninterruptible Switching Power Supply 12V 120W 110V-240V to 13.5V DC 50/60Hz with Battery Interface for Charging"
When you remove mains power it switches over instantly enough that the computer doesn't notice. There's no serial port on it so the computer has no way of knowing that it's on battery - but it was also only $26 shipped. No wires or battery or anything. I happen to have a few of the trimpot breakouts specifically for setting voltages, so i just made sure that when the PC was powered it was getting the correct voltage without sagging below 12.2ish under load at the output terminal of the PSU. It also has a little trimpot on the board for adjusting the voltage.
P.S. I'm not sure if Drok has a lot of knockoffs or not, i do know that i like that brand well enough, never had anything bought from them break in a weird way. I have slagged a few of their "waterproof" 24VDC boost converters, though!
it's not "that" steep once You consider the form factor and the technology used.
Generally the most You can get from a PSU this size would be those forementioned USB-C PD bricks. Those would these days get You at max about 100W for probably not less than 50-60USD (cheap Chinese models, more if branded).
Multiply that 2.5x (250W instead of 100W) and suddenly You're pretty close to the price.
We need a new ATX standard with external power bricks and smaller components. Giant ATX cases are unnecessarily huge, but laptops are too small and noisy. There's not much of a middle ground.
Like another poster said, Mini-ITX can be fairly small; I've got some 3.3L cases (includes a 150W power supply). My case has room for a 2.5" drive and a laptop optical drive (kind of, there's a related model that has an opening for the optical drive, mine just has the mounting place for it), you could get a smidge smaller if you omit that. There are smaller cases especially if you have and don't count an external power supply. If you do MicroATX including a MicroATX case, that's meaningfully smaller than ATX but there's no price premium. If you want to get smaller, the CPU coolers are the tricky bit, and I'm assuming you're ok with integrated graphics, GPUs and their coolers are pretty immense as well.
There's plenty of middle ground. In terms of size, you have Mini ITX as pointed out by another comment, and there's MicroATX which is perhaps more common than regular ATX. And of course there are several mini systems like the Mac Mini, Intel NUC series, and derivatives/copies of the NUC.
There are a lot of case options for small Mini ITX systems, I'm using an NCase M1 which is a 12-13L by volume case. There are smaller cases, but the smaller the case, the less flexible it is with configurations, which is one reason they large ATX cases are still popular; it seems like a lot of enthusiasts like clear side panels and rgb light shows and so forth, and a tiny case isn't as exciting.
There are also multiple PSU size options. The NCase M1 I mentioned can use a regular ATX PS, but an SFX power supply fits better; SFX seems like maybe half the volume of a regular ATX PS. There is also SFX-L, which is a bit bigger so it can house a larger fan. These smaller PS standards are typically lower power, although you can get 650W+ SFX supplies now I think. Silverstone and Corsair were regarded as having the best SFX supplies last time I was looking.
Finally, there are a couple of options for external power bricks like you suggest. As mentioned elsewhere there is a PicoPSU which is a DC/DC converter the size of a 24 pin ATX socket. It just plugs into the ATX socket on any regular ATX-compatible motherboard and has some cables attached to the sides for peripherals. There's also the 'Thin Mini-ITX' standard, which is I think intended for digital signage and industrial stuff, but if your requirements are modest you can use these for a desktop also. They integrate a DC/DC converter and use a 19V laptop ac adapter. The ones I've seen are best suited to on-chip graphics and m.2/msata drives, though.
There are plenty of products, but they're all underwhelming. Form factor and position of all the key components is so unfortunately mismatched, that no matter how you arrange them, there has to be a ton of wasted space.
It doesn't help much that you can have a small motherboard. You will need a CPU cooler stick out the middle of it, which already takes most of the space you have above MB's footprint. If you insert a GPU without a riser cable, you'll have to move the PSU to the side of the MB, and that's already almost as chonky as a regular ATX. So you're forced to deal with airflow-choked GPU, low-profile coolers, and no room for a powerful PSU.
If you instead opt for an easy-to-cool CPU and no discrete GPU to save space, it's still a massive box for a computing power of a tablet.
I remembered earlier there is an alternative GPU form factor for laptops called MXM. You can get desktop boards that accept these, I think they are called Micro-STX or Mini-STX. They are small, and the GPU is a flat module that plugs in more like a daughterboard than a PCI card. You're still looking at low-power CPU though.
I'm not sure what your vision looks like, to be honest. I think you want a laptop without the integrated screen and keyboard. That's a NUC, IMO; if an integrated or laptop-grade GPU isn't good enough, you'd want to do eGPU over thunderbolt I guess.
Maybe there could be some use if the external brick could be standard, so you'd only have to carry the actual computer.
But I personally would much prefer having to lug around a marginally bigger box instead of two smaller ones. Fewer cables to trip over, etc.
Also, if the case is a bit bigger, it will probably be able to house a bigger cooler, so it should be quieter, if I'm looking for a powerful computer.
If I'm OK with a regular middle of the road setup, there already are plenty of options from OEMs. I'm thinking HP Desktop Minis. Dell, Lenovo and Fujitsu also have similar offerings, though I'm not familiar with them. They can be a bit noisy under load, though.
scoff all you want, this was the plot of The Matrix!
(the original script was written with the sensible "using humans as a biological computer" angle but they worried audiences wouldn't get that newfangled computer thing in the basically prehistoric year of 1999, so they changed it to be humans generating power which... isn't how thermodynamics works!)
You could have combined it with Idiocracy - all the people in the Matrix act slow and dumb because most of their brainpower is being used to run weather simulations or whatever you'd do with a world-wide supercomputer.
I upvoted at the time but I just wanted to mention that I've scrolled through my comments/replies a few times and I've been chuckling every time I read it. ;)
been kind of a crappy couple weeks for me due to family illnesses and it did bring a smile to my face. feels like a "the matrix has you" sketch from the flash player days...
Is it just me or are the size benefits of GaN power supplies overblown? The 100w GaN type-c charger for my new laptop is less than ten percent lighter than the 100w charger for my decade-old Dell, while being six times more expensive to replace.
It might be about thirty percent smaller by volume. It's not any more convenient to carry around because instead of being a candy bar shape it's perfectly square and actually wider than the old one. While not related to it being a GaN charger, it being a permanently attached type-c connector is a recipe for disaster considering how much more delicate it is than a traditional laptop charger. I'm probably going back to a ThinkPad for my next laptop and the charger connector is not an insignificant reason why.
I have a laptop that draws 240W over a square slim tip, and recently saw a 240W GaN power brick. Like the photo in the article, it's comparable to an iPhone in size, but what prevented me from buying it was the weight (400g) and the price ($155 IIRC).
I think the sweet spot of GaN is in wall adapters that deliver 18-45W over USB-A/C for mobile devices rather than PSUs where the size/weight doesn't matter as much.
I actually have a 100W GaN charger for my 100W Razer Stealth 13''.
Super compact and great for travel. The new Razer models actually come with the GaN charger included!
GaN stuff is also used in the smallest and highest power compact tx power amplifiers in the rf chain for the buc/sspa on two way geostationary satellite terminals now. Some of the BUCs now are 1/3 the size of 12 years ago.
Other small and dense terrestrial microwave and millimeter wave things use gan power amps too.
94% efficient! When I started building PCs it was common to see 60-75% if you weren't inside a very narrow window of optimum load. It's mind-blowing how efficient electronics have become.
If I recall correctly GaN transistors also just generally are better in a lot of metrics. Faster switch times, Lower resistance, Higher permissible voltages, etc. It really does look like a miracle technology.
I would argue probably not. GaN has a higher bandgap voltage (3eV iirc... 1eV for Silicon), which means a CPU would need to be run at a higher voltage.
As a quick rule of thumb for huge transistor count ICs:
Power (heat) = freq*Voltage^2
I won't go into detail, but you can see how for a CPU designer decreasing voltage is critical to increasing speed. Remember a decade ago when CPUs were like 1.2V and we hit this ~3GHz "wall"? But now due to breakthroughs in process nodes, CPUs are running I think ~0.8V but boosting up to 5GHz.
If we make the same CPU on a GaN process, the transistors would probably need ~3V to switch, and thus need to be run about 9x slower to meet the same package power (or I guess you could run it at the same speed but then try and figure out how to cool a 9x higher TDP CPU).
Furthermore, GaN is difficult to manufacture into a monocrystaline perfect lattice compared to Silicon. You can image that for modern 7nm/5nm nodes, where there are sometimes angstroms of distance in a transistor, having a foundation full of defects can be devastating to the yield.
Power electronics is a totally different domain with different challenges. In this area GaN excels, but for ICs I don't think it makes sense. Let's see in 20 years though. GaN is relatively new compared to Silicon and might just need some further refinement.
Just my 2c though. Someone correct me if I'm wrong.
On the other hand GaN is much more tolerant of hight temperatures than regular resistors, so who knows which way the balance would fall?
Of course GaN is a much newer technology too so I imagine it'd have some serious catching up to do before it gets to the scales where it'd be useful for CPUs.
- you need a high breakdown voltage, so that for a given voltage you want to switch you can make the transistor channel as short as possible; shorten the physical distance that charge carriers have to flow in the semiconductor.
- you need a high maximum drift velocity, which governs the rate at which charge carriers can flow through the semiconductor
Those contribute to reducing the on-resistance of the transistor, thereby decreasing its heat output for a given size.
I think the chief limitation here is the ATX standard itself. Modern devices could make do with a single 12V rail (especially at this wattage), that would reduce the cabling and simplify the PSU circuitry as well.
A lot of prebuilt OEMs and consoles and not to mention laptops already use this approach.
On the other, my issue is that motherboards are already one of the least reliable components in your PC, and introducing even more complications to them just makes the situation (and the cost of replacement) worse
Going to only 12V power to the motherboard doesn't actually make them much more complicated, or any more complicated really. Like half of a modern motherboard design today is just power supplies anyways, as all CPUs will do voltage scaling to save power. It's not like your CPU takes 3.3V input directly, most are running in the 0.8-1.5V range, even DDR4 is 1.2V, and the CPU is the majority of the consumption on the actual motherboard (high power graphics cards usually have their own 12V input connector, the PCIe edge cannot transfer enough).
I expect motherboards could be more reliable if there was a standard 12v to 5v, 3.3v, 1.5v etc pluggable converter that they all used. It could cut down on E waste. Instead of having to discard an entire motherboard, the low voltage converter board could be swapped out and repaired/discarded. The same companies that make ATX power supplies could also make the discreet low voltage converters. ATX innards could be smaller, less wiring between components.
No that's silly, we should continue to use a design from 1995, itself replacing a design from 1981.
Well, sure that'd be nice, but it would add quite a lot of cost. High current carrying connectors are not free.
You can buy a nice AMD Ryzen motherboard for like $80 retail (Newegg shows $59 is where new unopened ones start). Normal electronics supply chain and shipping margins means it cost roughly half that to manufacture it. So on a $40 bill of materials and labor cost if you add even just $1 to make something better/modular/whatever then you're adding a significant amount in terms of percentage cost increase.
As much as reducing electronics waste is a worthy goal, the economics of it aren't aligned quite yet in today's world.
Could be denser. Instead of a big passive EMI filter, use an active one (noise cancelling, essentially).
It's a little baffling why they aren't more widely used, they aren't that complicated. https://u.dianyuan.com/bbs/u/17/1086016427.pdf is an example. It's almost comically simple: connect a current sensor, a high-pass filter, and an opamp controlling a transistor. With some thought it could probably be cut down even more.
I think TI has integrated this into their controllers already.
Consumer electronics are just so hilariously bleak. Why use the smart option when a cheap one almost does the job too? That would be overengineering and everyone can do that! Only the smartest engineers know how to deliver maximum value to shareholders while offloading the maximum possible externalities!
Well the big electrolytic caps you need for the passive filters are infamously unreliable which is why you see everyone trumpeting their "Japanese" brand capacitors which are supposed to be better.
The caps you need for the active filter are the tiny solid ceramic ones that are basically bulletproof except in high vibration environments. The ICs needed are similar.
This supply goes to quite some effort to have a good power factor and filter harmonics sent to the grid... But why?
Grid operators typically have laws in place saying how many harmonics you're allowed to inject, and for stuff under a few kilowatts it's totally fine to just have a bridge rectifier straight to a capacitor. That's what every other electronic device in your house will do.
If you're making a high efficiency power supply, you'd probably want that to be a synchronous rectifier to get 1% or so more efficiency, but it would still only be drawing current on the peaks of the sine wave.
But I don't see why you'd want to go to much effort to make your current draw a nice sine wave rather than a series of peak-chopping spikes. Is it to save money on copper in the power supply wire perhaps?
> and for stuff under a few kilowatts it's totally fine to just have a bridge rectifier straight to a capacitor. That's what every other electronic device in your house will do.
The EMC Directive mandates compliance with IEC 61000-3-2 which certainly requires you to do a little bit more than hook up a bridge rectifier to the grid.
Difficult to imagine the size from a photo with a phone (maybe it's due to me being a user of Android, idk). I'd prefer to see it next to previous small power supplies—because I'm vaguely sure I've seen some of comparable size and wattage for NASes, and my shopping for them was ten years ago. However, this one is likely considerably slimmer in height.
Ah, indeed I should've taken a look at the manufacturer site. However, I'm pretty sure that there is a format narrower than FlexATX from the picture — because I was thinking of buying a PSU like that for a petite NAS. (Until I learned that there are small, silent and cool external PSUs, similar to ones for laptops.)
Looks like the market niche is quite narrow for that. 250W is barely enough to power a desktop computer with onboard graphics. So compact office PCs it is?
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[ 4.1 ms ] story [ 234 ms ] threadIt's been such a great synergy. Energy efficiency has been a concern already yes, but I really view usb-c chargers as pushing the consumerization & massification & development of this technology to the superb, common, un-exotic levels it's come down to. We just got tired of doing less good, actively explored trying to use a somewhat harder to drive switching semiconductor, & have reaped great rewards. Miniaturization mandated optimization & we all win. I really think the interchangable-parts/modularity & resulting competition that usb-c begot started this ball rolling.
(Hoping USB-PD, with it's bump from 20 up to 48V, once again proves another huge win!)
Little Box Challenge went the other direction: instead of taking AC and producing DC power, it was an inverter that took DC power and produced AC output. It had to output 2kW and be smaller than 655 cubic centimeters (cc's). The winning Red Electrical Devil's team got 3x more dense than this[2]! 240 cc's! While inverting 2kW of juice. Second place was 340ccs.
I don't know whether we'd argue this DC->AC is harder/easier than an ATX supply (AC->DC) (probably not?) but this was quite an impressive competition, almost a decade ago, that resulted in probably some of the most power-dense, highest-efficiency power conversions that humanity has ever gotten up to. For compare, this 250W unit is 212cc's. 8x less power conversion, 88% the size.
The Little Box Challenge designs were published, so there's a ton of great reading. Alas, Google frakking let the damned site bitrot off the net?! Sooo, head to archive.org[3] to read the team's writeups. From the winning CET Red Electric Devils writeup:
> GaN transistors have many very interesting electrical characteristics (low Rds_on, low Qgate and Cds, ultra low Qrr); these create technological advantages over current MOSFET and IGBT devices (small size and low production costs). Unfortunately, they also have serious drawbacks due to their very fast switching characteristics: they are challenging to drive and require sensitive electromagnetic noise management. Another pitfall is the high voltage drop due to the reverse current when the GaN is turned off. The solution selected to overcome these difficulties is to control all the GaN transistors using soft switching for the entire operation range.
[1] https://news.ycombinator.com/item?id=8070215 (271 points, 8 years ago, 138 comments)
[2] https://ai.googleblog.com/2016/02/and-winner-of-1-million-li...
[3] http://web.archive.org/web/20171006105655/https://littleboxc...
I'm not sure how much power it can handle continuously in a pure passive-cooling mode.
What sort of power an electric drivetrain can handle for a burst of acceleration lasting a few seconds versus what that same drivetrain can handle as a continuous load are two very different things.
The same even applies with combustion powered cars too, if you look at the pickup truck market you'll see massive power numbers on every manufacturer's diesel pickups. If you look at their chassis-cab commercial trucks those same diesel engines are often derated by 30-50% compared to the pickups even while being equipped with larger cooling systems. That's because the commercial variants are rated to perform to spec all day every day where the pickup version just needs to put a grin on the owner's face when they floor it off the line and then occasionally tow a boat or something.
The little box challenge was significantly harder, primarily due to the ripple requirements on the DC side. This is not an issue in the same sense in the AC->DC case, because you don't have that problem there (you have other ripple considerations that might look similar, but are not (PFC and ripple on the output)). Usually you would require a lot of capacitance to solve the ripple issue for DC->AC and the winning team had a very interesting way of solving it without the use of very large capacitors.
The LBC was misshapen because they had an odd requirement: Be single-phase. A three-phase inverter (or rectifier) naturally has low DC ripple and is both more compact and more efficient than a single-phase inverter at all power levels. All of the winning solutions had extra energy storage elements which added inefficiency and bulk which a three-phase inverter would not have needed.
With that in mind, the LBC was a little silly. A three-phase machine at the same power level would have been much smaller than any of the "winning" designs.
A high-efficiency ATX power supply has additional requirements that the LBC didn't need to meet: Isolation. This implies the use of a transformer to protect the low-voltage DC side from the AC side. They typically accomplish this by rectifing AC, using a transformer-isolated unidirectionally optimized DC/DC supply to 12V, and then provide a handful of lower-power DC/DC converters to derive the other voltage levels used by ATX. A modern unisolated DC->AC machine is effectively symmetric in its power flow, and also functions as an AC->DC machine.
By using a higher frequency, the transformer can be much smaller and more efficient. If they were doing mains 60hz AC the transformer would be substantially larger.
I forget if they also step the supply side DC voltage up too…
They do, but they don't have to. The front-end rectifier boosts the voltage up to 400-450 VDC. This way, most of the components can be optimized for a single world-wide compatible machine that is capable of rectifying 230VAC.
In principle, you could squeeze out a bit of efficiency (or cost) by producing a North American market machine that was optimized for 120V and a separate machine optimized for 208/230V. In practice, supply chain simplification reduces overall per-unit costs, so just about everything is designed as a single machine for world-wide markets. Only the plugs change. For ATX, only the cord shipping in the box changes.
https://en.wikipedia.org/wiki/Light-emitting_diode#Blue_LED
I wonder what new engineering knowledge has emerged about gallium nitride that allowed it to become such a recent force in power supply electronics.
I didn't know that gallium nitride is transparent.
https://en.wikipedia.org/wiki/Gallium_nitride
It's been known for some time that GaN has a superior electron mobility number (which, effectively means you can get a better/smaller/lower impedance/faster switching device depending on which tradeoff you want). Problem is, getting reasonably good process control has been challenging. It appears some folks in the industry have been overcoming that challenge, therefore we're seeing the results of that.
Of course, they all purport to offer a warranty, but if you try to claim, they will not honor it. They will claim it's because you bought from Amazon and they don't warrant Amazon purchases (despite this being their main retail outlet, and the fact that they advertised the warranty IN the Amazon sales materials). Or something similar.
I constantly expect failures. This seems like an absurd task I'm putting them up to. But they are all still alive & doing the job.
I've had a kill-a-watt so I can see their power consumption. A large amount of their life is spent ~60 watts, but there's definitely hours on end & heavy usage days, where they go up to or stay at 90+.
My anecdotal data looks different than yours.
Yes, there is an EU law that says retailers are responsible for 2 years(6 in a some cases) for any item they sold......but only to rectify any manufacturing defects. The law additionally states that any defect found in the first 6 months is presumed to be a manufacturing issue, anything after the first 6 months it's the responsibility of the customer to prove that the product has failed due to a manufacturing problem. I'm sure you can appreciate that this can be very hard to do.
It's not a "warranty" in the sense that most people mean warranty. If your laptop fails 18 months after purchase, the retailer only has to fix it if you can prove that it failed due to a manufacturing defect. It's different to manufactuer's warranty, which usually covers any defect no matter the reason.
And yes, there is also the law that states that products should last a "reasonable" amount of time - but what is reasonable is not a strict definition, and again, unfortunately sometimes has to be argued in small claims court. It's not so straigtforward.
I have used warranty frequently after 6 months and never had to prove it is a manufacturing defect. Of course, if you buy at some shady webstore or known-bad retailer, you might have more issues.
Some of the power-tool brands are beginning to make USB-C devices, those chargers should be reliable also. Here's Dewalt: https://www.dewalt.com/product/dcb094k/usb-charging-kit
Companies selling under brands want a premium for them (Anker, Aukey) and "no name brands" you can actually put a little confidence into (Ugreen, Blitzwolf) are, for some reason, rare.
So, you charge your laptop at 100W means 20V*5A, then connect a phone that can only negotiate to 9V. Now your laptop can, at best, only get 45W. But laptop and phone might also have to share the same 5A, meaning something close to what you described. (or, your laptop might not support 9V ... in which case I'd guess one of the devices would disconnect?)
You might be better off using a USB-A port if the charger has one, then your laptop could perhaps remain at ~100W and your phone might still get ~10W. (Assuming charger and phone doesn't also have quickcharge which might complicate it further). Or, perhaps charge your phone via your laptop (yes, negates the point of a multiple-port charger, but if you are in hurry - otherwise, slow charging is preferably anyway)
A good review will test this, and a good product page will specify this (but if your are not looking/thinking about it it is easy to miss).
I also have a 60W Satechi travel charger that's been powered-on 24/7 for 3 years now without the slightest hint of a problem. It's even been buried under cushions for hours at a time.
The only charger I've had actually die was a Hama-branded device. Hama is the cheapest possible Chinese junk the brand can find.
They’ve been selling a 400W (still fanless!) DC-DC version for years and it’s only 160x51.5x26mm : https://hdplex.com/hdplex-400w-hi-fi-dc-atx-power-supply-16v...
I use it to power my CPU+mobo but I also have a couple of server PSUs further away to power my 3090 over several pairs of THNN. It’s far from a SFF build, but it can be totally silent.
This in no way meets the atx form factor for power supplies, neither the original, nor the 12V version. Like I could forgive it if it failed to be a rectangular prism in favor of having more open space, as long as it had a frame with proper mounting points.
And I could also forgive it if they went with the rectangle, but far shorter than the official 140mm depth (that has always been mandatory per intel specs), given that the market already accommodates non-conforming lengths, and this could be made to not require the bottom of case mounting holes, allowing for absurdly short lengths.
But the photos show none of that, and just a fully custom form factor, without any apparent mounting mechanism.
This is an ATX power supply. It is just designed for very small cases that would never be able to accommodate the existing standard configurations.
Did you just pull this out of nowhere?
Look at ATX Specification v. 2.01 section 4.1, page 18-20. It specifies the "required overall dimensions and general form factor of an ATX power supply," with or without special airflow ducting (emphasis in original).
The linked PSU in the OP clearly does not meet this form factor.
Perhaps they removed it in a revision? That seems like a silly idea…
Can someone explain to me why 48V? Is there something special with 48V or beyond? The reason I ask is because some cars now have electric turbos and the manufacturer had to switch to a 48V system. Just curious what the benefits of higher voltage is and if 48 is somehow special.
Thanks in advance.
I seem to recall that somewhere around 50 volts is a magic number from a safety/regulatory perspective. It might also have something to do with semiconductor breakdown voltage, but maybe I'm out of date on that.
Specifically, 50 volts is approximately the threshold above which electricity can pass through the skin and shock you. Lower voltages will only shock humans if they have a way to bypass some of the skin, like wounds or tight-fitting metal jewelry. Otherwise, the resistance of skin is high enough to prevent the flow of electricity. That's why you can touch both terminals of a 12V car battery at the same time and almost certainly not be shocked.
One of the things that can “get you” with these higher voltage systems is you can’t use them to jumpstart the present majority of cars. While I’ve yet to actually see a higher voltage car, I would hope they’d put warnings by the battery to remind the user that “hey, don’t try to jumpstart your friends car with this battery!”
I can see this being really good for (for instance) boxes like my fileserver which has a 65W TDP i3 in it and a bunch of SSDs, or compact media boxes that just have a processor and iGPU.
Unfortunately the way things are going in the world of PCs, you aren't going to power much of a modern dGPU from that.
Edit: Yes, the "ATX12VO" spec.
I have a desktop HP that has a standard-sized PSU but has a weird connector that only plugs into the motherboard. The drives are powered from a separate connector that also plugs into the motherboard. And the PSU - MB connector is much smaller than standard ATX.
There are also boards like this that have the RAM mounted flat, a lower profile set of ports on the back, and take in 19v DC: https://www.asrockind.com/en-gb/IMB-193
You'd have to make something custom, but I think it would be much simpler than typical heat sinks. With air cooling, the vertical placement would be ideal, since convection will tend to suck cool air from the bottom and release it on the top. (I think the iMac does/did this). Even for water cooling, it would be simpler with far fewer turns in the pipe. Plus, I just like the idea of laying everything out flat instead of the weird 3-D origami that is modern PC design.
You fix a PSU cause you know what you're doing and have the time, not because it's economical to do for someone else
Why is it that I've never heard of a power supply repair technician in a data center?
If it costs $20 to fix a $100 power supply, why would you replace it?
I don't think small cost savings like that are going to be implemented simply because it makes the operation more complex without landing any manager a big fat bonus.
Unless I'm grossly underestimating the failure rate of those supplies?
I wonder if the vendor would void the warranty and that would have any consequences.
Does you DC get around 125 failures per month?
For PSUs >1000 watts, I found that server supplies are cheaper both on a relative (more watts / dollar) and absolute cost basis than ATX form factor supplies.
There's probably more legitimate demand on the commercial side for >1kw PSUs so they can enjoy larger economies of scale.
- If your hardware hasn't reached EOL, it's probably under a warranty or support contract. So you just let your provider swap/fix it.
- If you tinker with anything and there's a problem with the rest of the hardware, they'll probably won't honor the warranty or support contract, or you could have problems with your insurance.
If it were a home user fixing a PSU... that's a different thing.
'Anyone' could be a penniless student and his time costs little, specialist may charge $40 per hour.
Also even ideal free market has cost of transaction, discoveravility, etc.
Hospitals have repair technicians, but why would you need one spesifically focusing on power supplies - he does not need different training or equipment
I’ve torn mine apart and replaced fans in them and such but I’ve never had to resolder any parts onto them. If a PSU dies - it tended to do it violently and was so cheap that it wasn’t worth doing it. All the name brand ones I’ve had never had any issues and same for the dozens of other people I knew. (Or computers I worked on or built or sold to others… or when I did IT and saw literally thousands of computers…)
Besides the capacitor only costing 10 cents and a new one around a hundred bucks the advantage for me was that I had fixed the whole thing within na hour or two including diagnosing the issue and the bike ride to the shop.
I was back on my PC that same night, and 5 years later that same PSU now well over ten years old is still going strong.
And they are standardised. Makes more sense to just replace them.
I don't necessarily need a smaller power supply, but options are nice.
I wonder if it is possible to run more than one board off the same PSU. I know you can run a board off multiple PSUs, but is the inverse true? If i ever get a new batch of these 25W TDP computers racked, having 2 of these connected to two UPS and 6 computers might be cool. It's just the ATX connector that needs population, i use NVME whenever possible, no GPU, no cards, just USB and ethernet onboard.
Absolutely. There's something I can't remember about signal lines that need to be set up, but yet, people have been running multiple computers off as single supply for a long long long time now.
Also worth warning people ahead of time, it's hard to predict what kind of specific power consumption a motherboard will have. There's so many power rails going in. 3.3V, 5V, 12V, -3.3V... Making sure that each rail is adequately rated for additional motherboards can be a challenge. Ideally one would test each supply line, one by one, to try & figure things out, & compare against rated specs of the power supply.
Intel's been pushing a new spec called ATX12VO, short for 12-volts-only, which does away with all the other rails & has the motherboard expect 12v. This would make it much easier to understand what power consumption is. I do seem to recall some of the new ATX specs (3.0?) also kind of expect power-consumers to declare how much power they expect to use, as a safety/planning feature, which could complicate this one easy-to-do hack (unless there's some way for the additional motherboard/motherboards to also declare their power draw). This might only be ATX3.0's new 12VHPWR connector, which works alongside PCIe 5.0-- not sure if it also impacts motherboards or not.
Buy a cheap inline tester and leave it always in? Something like: https://www.google.co.nz/search?q=Power+Supply+Tester+Digita...
So basically I wouldn't worry about motherboard compatibility due to 5v, 3.3v, and -3.3v rails - there just isn't much of anything still being done on those rails, and the things that do use it pretty much are the same across motherboards (because they're things that are plugged into the motherboard, not the motherboard itself).
The most important 5V rail is 5VSB - it powers wake-on-LAN and on some systems wake-via-bluetooth. The interesting question is, is it more efficient to always let 12V->5V regulators run for 5VSB or to use an extremely small separate regulator?
My main appreciation for ATX12VO (12 volts only) is the MB can choose to right size the 5V and 3.3V rails appropriately. M.2 slots are driven from 3.3V only (even if M.2 devices step it up or down for their specific uses). A board with 4 M.2 slots will have a different potential 3.3V power demand than a board with only 2 slots. Typically, a decent board will have 1 M.2 2230 A or E slot for WiFi, and 1-2 M.2 2280/22110 M (and rarely B) slots for M.2 storage. PCIe x16 lanes will have 9W of 3.3V, as part of their 75W total power (the remaining 66W is 12V).
As noted earlier, 5V is heavily I/O driven. A board with 15 USB ports can expect to need more 5V than a stingy board with only 8 (both are accounting for front I/O headers).
I'd rather the MB have to right-size the 3.3V and 5V rails, than forcing every PSU to include copious amounts of 3.3 and 5 just to cover every edge case.
Sure, it's a tiny bit of potential efficiency. It's also passing a bit of cost from the PSU to the board itself. Sadly, it does seem ATX12VO's main impact will be lost. OEMs are going to continue with their custom PSUs with unique connectors and the DIY vendor + consumer market has largely turned their backs to this.
To complicate this further, full system power-off is not the only time you want to do wake-on-lan... if you want to wake from system sleep then you have to be running the 12V rail anyway, because that 12V rail drives the VRMs which drive Vcore and Vmem. No 12V rail means you lose your memory and CPU state...
As such I don't think you can really frame this as "having a separate 5V regulator with the 12v rail turned off", or at least that use-case must exist in addition to the deep-sleep use-case, it cannot supplant it entirely.
Anyway though, power-supply 5V rails are usually much much larger than they need to be, and that has higher loss inside a transformer. Even if you make that a solid-state thing inside the transformer, moving power at 5V is less efficient than moving it at 12V and stepping it down at the point-of-consumption. So actually the answer is probably that it's more efficient to always run a step-down regulator.
When you remove mains power it switches over instantly enough that the computer doesn't notice. There's no serial port on it so the computer has no way of knowing that it's on battery - but it was also only $26 shipped. No wires or battery or anything. I happen to have a few of the trimpot breakouts specifically for setting voltages, so i just made sure that when the PC was powered it was getting the correct voltage without sagging below 12.2ish under load at the output terminal of the PSU. It also has a little trimpot on the board for adjusting the voltage.
P.S. I'm not sure if Drok has a lot of knockoffs or not, i do know that i like that brand well enough, never had anything bought from them break in a weird way. I have slagged a few of their "waterproof" 24VDC boost converters, though!
Generally the most You can get from a PSU this size would be those forementioned USB-C PD bricks. Those would these days get You at max about 100W for probably not less than 50-60USD (cheap Chinese models, more if branded).
Multiply that 2.5x (250W instead of 100W) and suddenly You're pretty close to the price.
There are a lot of case options for small Mini ITX systems, I'm using an NCase M1 which is a 12-13L by volume case. There are smaller cases, but the smaller the case, the less flexible it is with configurations, which is one reason they large ATX cases are still popular; it seems like a lot of enthusiasts like clear side panels and rgb light shows and so forth, and a tiny case isn't as exciting.
There are also multiple PSU size options. The NCase M1 I mentioned can use a regular ATX PS, but an SFX power supply fits better; SFX seems like maybe half the volume of a regular ATX PS. There is also SFX-L, which is a bit bigger so it can house a larger fan. These smaller PS standards are typically lower power, although you can get 650W+ SFX supplies now I think. Silverstone and Corsair were regarded as having the best SFX supplies last time I was looking.
Finally, there are a couple of options for external power bricks like you suggest. As mentioned elsewhere there is a PicoPSU which is a DC/DC converter the size of a 24 pin ATX socket. It just plugs into the ATX socket on any regular ATX-compatible motherboard and has some cables attached to the sides for peripherals. There's also the 'Thin Mini-ITX' standard, which is I think intended for digital signage and industrial stuff, but if your requirements are modest you can use these for a desktop also. They integrate a DC/DC converter and use a 19V laptop ac adapter. The ones I've seen are best suited to on-chip graphics and m.2/msata drives, though.
It doesn't help much that you can have a small motherboard. You will need a CPU cooler stick out the middle of it, which already takes most of the space you have above MB's footprint. If you insert a GPU without a riser cable, you'll have to move the PSU to the side of the MB, and that's already almost as chonky as a regular ATX. So you're forced to deal with airflow-choked GPU, low-profile coolers, and no room for a powerful PSU.
If you instead opt for an easy-to-cool CPU and no discrete GPU to save space, it's still a massive box for a computing power of a tablet.
I remembered earlier there is an alternative GPU form factor for laptops called MXM. You can get desktop boards that accept these, I think they are called Micro-STX or Mini-STX. They are small, and the GPU is a flat module that plugs in more like a daughterboard than a PCI card. You're still looking at low-power CPU though.
I'm not sure what your vision looks like, to be honest. I think you want a laptop without the integrated screen and keyboard. That's a NUC, IMO; if an integrated or laptop-grade GPU isn't good enough, you'd want to do eGPU over thunderbolt I guess.
But I personally would much prefer having to lug around a marginally bigger box instead of two smaller ones. Fewer cables to trip over, etc.
Also, if the case is a bit bigger, it will probably be able to house a bigger cooler, so it should be quieter, if I'm looking for a powerful computer.
If I'm OK with a regular middle of the road setup, there already are plenty of options from OEMs. I'm thinking HP Desktop Minis. Dell, Lenovo and Fujitsu also have similar offerings, though I'm not familiar with them. They can be a bit noisy under load, though.
[1]: https://en.wikipedia.org/wiki/Generative_adversarial_network
(the original script was written with the sensible "using humans as a biological computer" angle but they worried audiences wouldn't get that newfangled computer thing in the basically prehistoric year of 1999, so they changed it to be humans generating power which... isn't how thermodynamics works!)
"And where did you learn about physics, Neo?"
"..... In the Matrix...."
been kind of a crappy couple weeks for me due to family illnesses and it did bring a smile to my face. feels like a "the matrix has you" sketch from the flash player days...
> Neo: "You won't do it, you need humans to survive."
> The Architect (phrased angrily and bitterly) "There are some levels of survival we are prepared to accept."
I think the sweet spot of GaN is in wall adapters that deliver 18-45W over USB-A/C for mobile devices rather than PSUs where the size/weight doesn't matter as much.
Other small and dense terrestrial microwave and millimeter wave things use gan power amps too.
Also < 0.4W idle. Wow.
Then again, 20kWh here, 20kWh there, it adds up.
As a quick rule of thumb for huge transistor count ICs: Power (heat) = freq*Voltage^2
I won't go into detail, but you can see how for a CPU designer decreasing voltage is critical to increasing speed. Remember a decade ago when CPUs were like 1.2V and we hit this ~3GHz "wall"? But now due to breakthroughs in process nodes, CPUs are running I think ~0.8V but boosting up to 5GHz.
If we make the same CPU on a GaN process, the transistors would probably need ~3V to switch, and thus need to be run about 9x slower to meet the same package power (or I guess you could run it at the same speed but then try and figure out how to cool a 9x higher TDP CPU).
Furthermore, GaN is difficult to manufacture into a monocrystaline perfect lattice compared to Silicon. You can image that for modern 7nm/5nm nodes, where there are sometimes angstroms of distance in a transistor, having a foundation full of defects can be devastating to the yield.
Power electronics is a totally different domain with different challenges. In this area GaN excels, but for ICs I don't think it makes sense. Let's see in 20 years though. GaN is relatively new compared to Silicon and might just need some further refinement.
Just my 2c though. Someone correct me if I'm wrong.
Of course GaN is a much newer technology too so I imagine it'd have some serious catching up to do before it gets to the scales where it'd be useful for CPUs.
There are two factors:
- you need a high breakdown voltage, so that for a given voltage you want to switch you can make the transistor channel as short as possible; shorten the physical distance that charge carriers have to flow in the semiconductor.
- you need a high maximum drift velocity, which governs the rate at which charge carriers can flow through the semiconductor
Those contribute to reducing the on-resistance of the transistor, thereby decreasing its heat output for a given size.
A lot of prebuilt OEMs and consoles and not to mention laptops already use this approach.
On the other, my issue is that motherboards are already one of the least reliable components in your PC, and introducing even more complications to them just makes the situation (and the cost of replacement) worse
No that's silly, we should continue to use a design from 1995, itself replacing a design from 1981.
You can buy a nice AMD Ryzen motherboard for like $80 retail (Newegg shows $59 is where new unopened ones start). Normal electronics supply chain and shipping margins means it cost roughly half that to manufacture it. So on a $40 bill of materials and labor cost if you add even just $1 to make something better/modular/whatever then you're adding a significant amount in terms of percentage cost increase.
As much as reducing electronics waste is a worthy goal, the economics of it aren't aligned quite yet in today's world.
It's a little baffling why they aren't more widely used, they aren't that complicated. https://u.dianyuan.com/bbs/u/17/1086016427.pdf is an example. It's almost comically simple: connect a current sensor, a high-pass filter, and an opamp controlling a transistor. With some thought it could probably be cut down even more.
I think TI has integrated this into their controllers already.
Sorry, pet peeve of mine.
The caps you need for the active filter are the tiny solid ceramic ones that are basically bulletproof except in high vibration environments. The ICs needed are similar.
This 'ultra compqct' only offers 1.18 watts/cm^3 in 2022.
While this might be the best on the market, it is far from what is technically possible.
Grid operators typically have laws in place saying how many harmonics you're allowed to inject, and for stuff under a few kilowatts it's totally fine to just have a bridge rectifier straight to a capacitor. That's what every other electronic device in your house will do.
If you're making a high efficiency power supply, you'd probably want that to be a synchronous rectifier to get 1% or so more efficiency, but it would still only be drawing current on the peaks of the sine wave.
But I don't see why you'd want to go to much effort to make your current draw a nice sine wave rather than a series of peak-chopping spikes. Is it to save money on copper in the power supply wire perhaps?
The EMC Directive mandates compliance with IEC 61000-3-2 which certainly requires you to do a little bit more than hook up a bridge rectifier to the grid.
Unless... the wiring is over ~30 years old, in which case it's Black + Red for Neutral and Live.
https://en.wikipedia.org/wiki/IEC_60446#Protective_earth_and...