Simon Willison’s Weblog

Two interesting examples of inference speed as a flagship feature of LLM services today.

First, Cerebras announced two new monthly plans for their extremely high speed hosted model service: Cerebras Code Pro ($50/month, 1,000 messages a day) and Cerebras Code Max ($200/month, 5,000/day). The model they are selling here is Qwen's Qwen3-Coder-480B-A35B-Instruct, likely the best available open weights coding model right now and one that was released just ten days ago. Ten days from model release to third-party subscription service feels like some kind of record.

Cerebras claim they can serve the model at an astonishing 2,000 tokens per second - four times the speed of Claude Sonnet 4 in their demo video.

Also today, Moonshot announced a new hosted version of their trillion parameter Kimi K2 model called kimi-k2-turbo-preview:

🆕 Say hello to kimi-k2-turbo-preview Same model. Same context. NOW 4× FASTER.

⚡️ From 10 tok/s to 40 tok/s.

💰 Limited-Time Launch Price (50% off until Sept 1)

• $0.30 / million input tokens (cache hit)
• $1.20 / million input tokens (cache miss)
• $5.00 / million output tokens

👉 Explore more: platform.moonshot.ai

This is twice the price of their regular model for 4x the speed (increasing to 4x the price in September). No details yet on how they achieved the speed-up.

I am interested to see how much market demand there is for faster performance like this. I've experimented with Cerebras in the past and found that the speed really does make iterating on code with live previews feel a whole lot more interactive.