Of course they're using the on-chip SRAM, why wouldn't they?
This is a press release from Cerebras about a Cerebras chip, ... of course they are using a Cerebras chip!
Is that not obvious?
https://www.cerebras.ai/blog/cerebras-cs-3-vs-nvidia-b200-20...
https://www.cerebras.ai/blog/announcing-the-cerebras-archite...
It is useless for inference, but it is great for training. It used to be more prominent on their website, but it is harder to find references to it now that they are mimicking Groq’s business model.