GPT-5.2 and GPT-5.2-Codex are now 40% faster

[OutOfHere]

OpenAI in my estimation has the habit of dropping a model's quality after its introduction. I definitely recall the web ChatGPT 5.2 being a lot better when it was introduced. A week or two later, its quality suddenly dropped. The initial high looked to be to throw off journalists and benchmarks. As such, nothing that OpenAI says in terms of model speed can be trusted. All they have to do is lower the reasoning effort on average, and boom, it becomes 40% faster. I hope I am wrong, because if I am right, it's a con game.

Starting off the ChatGPT Plus web users with the Pro model, then later swapping it for the Standard model -- would meet the claims of model behavior consistency, while still qualifying as shenanigans.

[tedsanders]

It's good to be skeptical, but I'm happy to share that we don't pull shenanigans like this. We actually take quite a bit of care to report evals fairly, keep API model behavior constant, and track down reports of degraded performance in case we've accidentally introduced bugs. If we were degrading model behavior, it would be pretty easy to catch us with evals against our API.

In this particular case, I'm happy to report that the speedup is time per token, so it's not a gimmick from outputting fewer tokens at lower reasoning effort. Model weights and quality remain the same.

[benterix]

> I hope I am wrong, because if I am right, it's a con game.

I don't think they perceive it as a con game, on the contrary. They say below: "we also recently reduced the thinking effort in ChatGPT. Our intent here was purely user experience, not cost savings."

They are not the only ones playing this game. Google did the same with Gemini Pro.

[scrollop]

OpenAI isn't the only one:

Anthropic:

https://marginlab.ai/trackers/claude-code/

[jxmesth]

Someone should create a daily benchmark site for Codex like they did for Claude

[bethekidyouwant]

I mean you can just run the benchmark again

[prodigycorp]

This is great.

In the past month, OpenAI has released for codex users:

- subagents support

- a better multi agent interface (codex app)

- 40% faster inference

No joke, with the first two my productivity is already up like 3x. I am so stoked to try this out.

[jswny]

How do you get sub agents to work?

[wahnfrieden]

this is for api only

[brianwawok]

Try Claude and you can get x^2 performance. OpenAI is sweating

[tmaly]

Over the weekend I was running the same prompt across GPT-5.2, Gemini 3, and Grok. Both Gemini 3 and Grok on thinking mode finished within 2 minutes. GPT-5.2 was just spinning its wheels for like 6 minutes.

[thadk]

It was probably from the other day when roon realized that normal people have it slower than staff.

Then from that they realized they could just run API calls more like staff, fast, not at capacity.

Then they leave the billion other people's calls at remaining capacity.

https://thezvi.substack.com/i/185423735/choose-your-fighter

> Ohqay: Do you get faster speeds on your work account?

> roon: yea it’s super fast bc im sure we’re not running internal deployment at full load

[simianwords]

It’s interesting that they kept the price the same while doing inference on Cerebras is much more expensive.

[diwank]

I dont think this is Cerebras. Running on cerebras would change model behavior a bit and it could potentially get a ~10x speedup and it'd be more expensive. So most likely this is them writing new more optimized kernels for Blackwell series maybe?

[chillee]

this is almost certainly not being done on cerebras

[thebigspacefuck]

Speed was always my main complaint, these models always felt really good but too slow. I’ll have to give them a try again.

[riku_iki]

tons of posts on reddit that they also significantly dropped quality

[samusiam]

There are always people on reddit saying such-and-such model quality significantly dropped. Every single day there's a post like this in one of the Claude sub-reddits. It's virtually never substantiated with reliable evidence.

[logicallee]

any ideas how they could get the speedup?