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they are using ethical training weights this time!!! /j
If there's a bingo card for model releases, "our [superlative] and [superlative] model yet" is surely the free space.
Benchmarks are favorable enough they're comparing to non-OpenAI models again. Interesting that tokens/second is similar to 5.4. Maybe there's some genuine innovation beyond bigger model better this time?
The more interesting part of the announcement than "it's better at benchmarks":

> To better utilize GPUs, Codex analyzed weeks’ worth of production traffic patterns and wrote custom heuristic algorithms to optimally partition and balance work. The effort had an outsized impact, increasing token generation speeds by over 20%.

The ability for agentic LLMs to improve computational efficiency/speed is a highly impactful domain I wish was more tested than with benchmarks. From my experience Opus is still much better than GPT/Codex in this aspect, but given that OpenAI is getting material gains out of this type of performancemaxxing and they have an increasing incentive to continue doing so given cost/capacity issues, I wonder if OpenAI will continue optimizing for it.

So, im working in some high performance data processing in Rust. I had hit some performance walls, and needed to improve in the 100x or more scale.

I remembered the famous FizzBuzz Intel codegolf optimizations, and gave it to gemini pro, along with my code and instructions to "suggest optimizations similar to those, maybe not so low level, but clever" and it's suggestions were veerry cool.

LLM do not stop amazing me every day.

I like that they waited for opus 4.7 to come out first so they had a few days to find the benchmarks that gpt 5.5 is better at
82.7% on Terminal Bench is crazy
A playable 3D dungeon arena prototype built with Codex and GPT models. Codex handled the game architecture, TypeScript/Three.js implementation, combat systems, enemy encounters, HUD feedback, and GPT‑generated environment textures. Character models, character textures, and animations were created with third-party asset-generation tools

The game that this prompt generated looks pretty decent visually. A big part of this likely due to the fact the meshes were created using a seperate tool (probably meshy, tripo.ai, or similiar) and not generated by 5.5 itself.

It really seems like we could be at the dawn of a new era similiar to flash, where any gamer or hobbyist can generate game concepts quickly and instantly publish them to the web. Three.js in particular is really picking up as the primary way to design games with AI, in spite of the fact it's not even a game engine, just a web rendering library.

LLM models can not do spacial reasoning. I haven't tried with GPT, however, Claude can not solve a Rubik Cube no matter how much I try with prompt engineering. I got Opus 4.6 to get ~70% of the puzzle solved but it got stuck. At $20 a run it prohibitively expensive.

The point is if we can prompt an LLM to reason about 3 dimensions, we likely will be able to apply that to math problems which it isn't able to solve currently.

I should release my Rubiks Cube MCP server with the challenge to see if someone can write a prompt to solve a Rubik's Cube.

It’s like all these things though - it’s not a real production worthy product. It’s a super-demo. It looks amazing until you realize there’s many months of work to make it something of quality and value.

I think people are starting to catch on to where we really are right now. Future models will be better but we are entering a trough of dissolution and this attitude will be widespread in a few months.

> It really seems like we could be at the dawn of a new era similiar to flash

We've been there for a while.... creativity has been the primary bottleneck

Are there faster mini/nano versions as well?
GPT is really great, but I wish the GPT desktop app supported MCP as well.

You can kind of use connectors like MCP, but having to use ngrok every time just to expose a local filesystem for file editing is more cumbersome than expected.

Not rolled out to my Codex CLI yet, but some users on Reddit claiming it's on theirs.
It's possible that "smarter" AI won't lead to more productivity in the economy. Why?

Because software and "information technology" generally didn't increase productivity over the past 30 years.

This has been long known as Solow's productivity paradox. There's lots of theories as to why this is observed, one of them being "mismeasurement" of productivity data.

But my favorite theory is that information technology is mostly entertainment, and rather than making you more productive, it distracts you and makes you more lazy.

AI's main application has been information space so far. If that continues, I doubt you will get more productivity from it.

If you give AI a body... well, maybe that changes.

25 years of shipping software, and IT absolutely increased productivity - just not for everyone, not everywhere. Some workflows got 10x faster, others got slower from meetings about the new tools.

AI feels the same. I'm shipping indie apps solo now that would have needed a small team five years ago. But in bigger orgs I see people spending 20 minutes verifying 15-minute AI output that used to be a 30-minute task they'd just do. Depends where you sit.

Just as a heads up, even though GPT-5.5 is releasing today, the rollout in ChatGPT and Codex will be gradual over many hours so that we can make sure service remains stable for everyone (same as our previous launches). You may not see it right away, and if you don't, try again later in the day. We usually start with Pro/Enterprise accounts and then work our way down to Plus. We know it's slightly annoying to have to wait a random amount of time, but we do it this way to keep service maximally stable.

(I work at OpenAI.)

Will GPT 5.5 fine tuning be released any time soon?
LETS GO CODEX #1
Looks good, but I’m a little hesitant to try it in Codex as a Plus user since I’m not sure how much it would eat into the usage cap.
Are you able to say something about the training you've done to 5.5 to make it less likely to freak out and delete projects in what can only be called shame?
When I ask GPT-5.5 about its knowledge cutoff date it says "August 2025". Really?
So according to the benchmarks somewhere in between Opus 4.7 and Mythos
What is the reason behind OpenAI being able to release new models very fast?

Since Feb when we got Gemini 3.1, Opus 4.6, and GPT-5.3-Codex we have seen GPT-5.4 and GPT-5.5 but only Opus 4.7 and no new Gemini model.

Both of these are pretty decent improvements.

Worth the 100% price increase over GPT-5.4?
For a 56.7 score on the Artificial Intelligence Index, GPT 5.5 used 22m output tokens. For a score of 57, Opus 4.7 used 111m output tokens.

The efficiency gap is enormous. Maybe it's the difference between GB200 NVL72 and an Amazon Tranium chip?

If it's a new pretrain, the token embeddings could be wider - you can pack more info into a token making it's way through the system.

Like Chinese versus English - you need fewer Chinese characters to say something than if you write that in English.

So this model internally could be thinking in much more expressive embeddings.

You need to compare total cost. Token count is irrelevant.
> GPT‑5.5 improves on GPT‑5.4’s scores while using fewer tokens.

This might be great if it translates to agentic engineering and not just benchmarks.

It seems some of the gains from Opus 4.6 to 4.7 required more tokens, not less.

Maybe more interesting is that they’ve used codex to improve model inference latency. iirc this is a new (expectedly larger) pretrain, so it’s presumably slower to serve.

I'm here for the pelicans and I'm not leaving until I see one!
Next up: Google I/O on May 19?

I have to imagine they'll go to Gemini 3.5 if only for marketing reasons.

Pricing: $5/1M input, $30/1M output

(same input price and 20% more output price than Opus 4.7)

Surprised to see SWE-Bench Pro only a slight improvement (57.7% -> 58.6%) while Opus 4.7 hit 64.3%. I wonder what Anthropic is doing to achieve higher scores on this - and also what makes this test particular hard to do well in compared to Terminal Bench (which 5.5 seemed to have a big jump in)
ARC-AGI 3 is missing on this list - given that the SOTA before 5.5 <1% if I recall, I wonder if this didn't make meaningful progress.
Yay. 5.4 was a frustrating model - moments of extreme intelligence (I liked it very much for code review) - but also a sort of idiocy/literalism that made it very unsuited for prompting in a vague sense. I also found its openclaw engagement wooden and frustrating. Which didn’t matter until anthropic started charging $150 a day for opus for openclaw.

Anyway - these benchmarks look really good; I’m hopeful on the qualitative stuff.