And if you are curious about the modern radiation hardened CPUs then the current state of the art ones are the MOOG BRE440 [0] and the BAE RAD5500 [1], 5545 [2] being the highest performance multi core one.
Even more interesting that they both use the IBM POWER architecture!
Current state-of-the-art rad-hard CPUs are made by AMD, Intel, and IBM, among others. Their server-grade CPUs have so much error resilience and protection in them that they would have been export-controlled rad-hard devices twenty to thirty years ago.
To my knowledge neither AMD nor Intel ship any processors that are rad hard or rad tolerant. For aerospace applications this is a very specific type of device which requires specific engineering work to achieve. You don't just get rad tolerant design through standard error correction and you definitely don't get rad hard without designing for it.
They're not advertised as such but they are. I don't have any current evals to hand but a 25-year-old paper that looked at things like the PIII concluded that "Intel processors verge on radiation-hardened devices" and another more recent one that "No apparent device degradation was apparent on any of the samples. Cumulative dose levels for exposures ranged from 1 to 17 Mrad(Si). For comparison, the ITAR level is 500 krad(Si). As noted, total dose and DR device tolerances exceed the ITAR limits for this [AMD A4-3300, 2011 vintage budget desktop CPU] off-shore fabricated design. To the best of the authors’ knowledge, AMD has not intentionally radiation hardened the device for these environments, but the technology itself supports these characteristics". IBM and Sparc CPUs are the same, tested under proton or neutron bombardment, but they don't publish dose rate figures, just FIT or MTTU.
Very interesting! Definitely some jargon I’ve not come across before.
“The chips were made on a n-on-n+ epitaxial substrate to provide latchup control, extensive guard rings around transistors were used and hardened oxides”
If this was copy-pasted, isn't it much more likely that it was copy-pasted from a document describing the performance of the SA3000 chip, than from a document that was written before the SA3000 was developed?
The only overlap from the document with the text you quote is the "106", which is a pretty common mis-formatting issue.
Interesting combination of 'remarkable' and 'wtf' that we fling nuclear weapons around with the computational equivalent of a couple of TRS-80s[1]. I can only imagine the sighs of relief from the devs when things like the MIL-STD-1750a and later rad-hard SPARC and PPC variants came along.
[1] yes...I know the TRS-80 had a z80, not an 8085. Close enough.
> Back in the late 1970’s and early 1980’s Sandia National Laboratory (in Albuquerque NM USA) began building the capacity to design, fab, and test IC’s at scale (packaging was handled by Fairchild and Allied Signal).
We need more of this kind of thing, generally: government agencies building up in-house technical capability, instead of outsourcing everything to contractors.
For instance: there should be a government-controlled pharmaceutical manufacturer of last resort. The clear benefits would be to provide extra capacity and prevent things like Martin Shkreli's scams with Retrophin/Turing Pharmaceuticals (https://en.wikipedia.org/wiki/Martin_Shkreli#Thiola_price_hi...).
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[ 0.27 ms ] story [ 51.4 ms ] threadEven more interesting that they both use the IBM POWER architecture!
0, https://www.moog.com/products/avionics/spacecraft-avionics/b...
1, https://en.wikipedia.org/wiki/RAD5500
2, https://web.archive.org/web/20190226111129/https://www.baesy...
Additionally, total dose is only one part of the equation. Single Event Effects (SEE) also must be mitigated.
You can read NASA JPL's ASIC design guidance for a brief intro.
https://parts.jpl.nasa.gov/asic/Sect.3.4.html#A0
“The chips were made on a n-on-n+ epitaxial substrate to provide latchup control, extensive guard rings around transistors were used and hardened oxides”
> An 8085 processor that could handle 1×106 rads of radiation with only a 25% reduction in performance, and 3×106 rads with a 40% drop.
Hmm, from where did they copy-paste this mangled scientific notation?
Ah here we are, pg. 37 (46 in PDF file): https://apps.dtic.mil/sti/tr/pdf/ADA063902.pdf
The only overlap from the document with the text you quote is the "106", which is a pretty common mis-formatting issue.
[1] yes...I know the TRS-80 had a z80, not an 8085. Close enough.
Clearly you meant the TRS-80 Model 100.
https://en.wikipedia.org/wiki/Apollo_Guidance_Computer
I seriously doubt you need to fabricate 50k CPUs for a single space probe, including backups, testing chips, etc.
We need more of this kind of thing, generally: government agencies building up in-house technical capability, instead of outsourcing everything to contractors.
For instance: there should be a government-controlled pharmaceutical manufacturer of last resort. The clear benefits would be to provide extra capacity and prevent things like Martin Shkreli's scams with Retrophin/Turing Pharmaceuticals (https://en.wikipedia.org/wiki/Martin_Shkreli#Thiola_price_hi...).