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Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

cerebras.ai

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Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#114

Has anyone with a lot of experience with Claude Code and sonnet-4 tried Claude Code with Qwen3-Coder? The fast times enabled here by Cerebras are enticing, but I wouldn't trade a speedup for a worse quality model.

haven't tried Qwen but used these "near instant token" like groq and another one that uses diffusion model to generate code via LLaMA and the results weren't satisfactory.

now if something like Gemini 2.5 pro or Sonnet 4 even can run on Cerebras generating tens of thousands of code in a few seconds, that could really make a difference.

Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#115
post #96
post #13

Earlier quoted context omitted.

Thinking can also make the responses worse; AIs don't "overthink", instead they start throwing away constraints and convincing themselves of things that are tangential or opposite to the task. I've often observed thinking/reasoning to cause models to completely disregard important constraints, because they essentially can act as conversational turns.

> start throwing away constraints and convincing themselves of things that are tangential or opposite to the task Funny that, when given too much brainpower, AIs manifest ADHD symptoms…

Validating if you have ADHD, but still an issue that is somehow glanced over by everyone who uses AI daily(?)

Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#116
post #72

They better not cheat me with a quantized version!

I tried the non-quantized version, and it was pretty bad at creative writing compared to Kimi K2. Very deterministic and every time I regenerated the same prompt I got the usual AI phrases like "the kicker is:", etc. Kimi was much more natural.

Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#117

Earlier quoted context omitted.

That's not how you would do it with Cerebras. 44GB is SRAM, so on chip memory, not HBM memory where you would store most of the params. For reference one GB200 has only 126MB of SRAM, if you tried to estimate how many GB200 you would need for a 2TB model just by looking at the L2 cache size you would get 16k GB200 aka ~600M$, obviously way off. Yes but Cerebras achieves its speed by using SRAM.

There is no way not to use SRAM on a GPU/Cerebras/most accelerators. This is where the cores fetch the data. But that doesn’t mean you are only using SRAM, that would be impractical. Just like using a CPU just by storing stuff in the L3 cache and never going to the RAM. Unless I am missing something from the original link, I don’t know how you got to the conclusion that they only used SRAM.

> I don’t know how you got to the conclusion that they only used SRAM.

Because they are doing 1,500 tokens per second.

Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#118

If this is the full fp16 quant, you'd need 2TB of memory to use with the full 131k context. With 44GB of SRAM per Cerebras chip, you'd need 45 chips chained together. $3m per chip. $135m total to run this. For comparison, you can buy a DGX B200 with 8x B200 Blackwell chips and 1.4TB of memory for around $500k. Two systems would give you 2.8TB memory which is enough for this. So $1m vs $135m to run this model. It's no…

I think you're missing an important aspect: how many users do you want to support?

> For comparison, you can buy a DGX B200 with 8x B200 Blackwell chips and 1.4TB of memory for around $500k. Two systems would give you 2.8TB memory which is enough for this.

That would be enough to support a single user. If you want to host a service that provides this to 10k users in parallel your cost per user scales linearly with the GPU costs you posted. But we don't know how many users a comparable wafer-scale deployment can scale to (aside from the fact that the costs you posted for that are disputed by users down the thread as well), so your comparison is kind of meaningless in that way, you're missing data.

Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#119

Earlier quoted context omitted.

Our chips don't cost $3M. I'm not sure where you got that number but its wildly incorrect.

So how much does it cost? Google search return $3m. Here's your chance to tell us your real price if you disagree.

He also didn't argue about the rest of the math so it's likely correct that the whole model needs to be in SRAM :)

Re: Cerebras launches Qwen3-235B, achieving 1.5k tokens per second

#120

If this is the full fp16 quant, you'd need 2TB of memory to use with the full 131k context. With 44GB of SRAM per Cerebras chip, you'd need 45 chips chained together. $3m per chip. $135m total to run this. For comparison, you can buy a DGX B200 with 8x B200 Blackwell chips and 1.4TB of memory for around $500k. Two systems would give you 2.8TB memory which is enough for this. So $1m vs $135m to run this model. It's no…

> We're still a few generations of hardware away I'm guessing.

I don't know; I think we could be running models "as good as" Claude Opus 4, a few years down the line, with a lot less hardware — perhaps even going backwards, with "better" later models fitting on smaller, older — maybe even consumer-level — GPUs.

Why do I say this? Because I get the distinct impression that "throwing more parameters at the problem" is the current batch of AI companies' version of "setting money on fire to scale." These companies are likely leaving huge amounts of (almost-lossless) optimization on the table, in the name of having a model now that can be sold at huge expense to those few customers who really want it and are willing to pay (think: intelligence agencies automating real-time continuous analysis of the conversations of people-of-interest). Having these "sloppy but powerful" models, also enables the startups themselves to make use of them in expensive one-time batch-processing passes, to e.g. clean and pluck outliers from their training datasets with ever-better accuracy. (Think of this as the AI version of "ETL data migration logic doesn't need to be particularly optimized; what's the difference between it running for 6 vs 8 hours, if we're only ever going to run it once? May as well code it in a high-level scripting language.")

But there are only so many of these high-value customers to compete over, and only so intelligent these models need to get before achieving perfect accuracy on training-set data-cleaning tasks can be reduced to "mere" context engineering / agentic cross-validation. At some point, an inflection point will be passed where the marginal revenue to be earned from cost-reduced volume sales outweighs the marginal revenue to be earned from enterprise sales.

And at that point, we'll likely start to see a huge shift in in-industry research in how these models are being architected and optimized.

No longer would AI companies set their goal in a new model generation first as purely optimizing for intelligence on various leaderboards (ala the 1980s HPC race, motivated by serving many of the same enterprise customers!), and then, leaderboard score in hand, go back and re-optimize to make the intelligent model spit tokens faster when run on distributed backplanes (metric: tokens per watt-second).

But instead, AI companies would likely move to a combined optimization goal of training models from scratch to retain high-fidelity intelligent inference capabilities on lower-cost substrates — while minimizing work done [because that's what OEMs running local versions of their models want] and therefore minimizing "useless motion" of semantically-meaningless tokens. (Implied metric: bits of Shannon informational content generated per (byte-of-ram x GPU FLOP x second)).

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