tetsuo@tetsuoai
Grok 4.5 goes public tomorrow. Here’s everything that’s known.
The model runs on V9, xAI’s new 1.5 trillion parameter foundation, roughly three times the size of the v8-small architecture behind Grok 4.3. It’s the largest model the company has shipped, trained on Blackwell GPUs at the Colossus cluster in Memphis.
Coding is the clear focus. Cursor’s developer data was added in supplemental training, and reinforcement learning has been improving the model daily alongside the Grok Build harness. The next foundation model already in training will have Cursor data included from the start of pre-training.
Elon calls it Opus-level, and says it’s faster, more token-efficient, and cheaper. It’s been in private beta at SpaceX and Tesla since June 28, with early internal evals reportedly at or above that mark. Public benchmarks land once the model does.
This is the first flagship under SpaceXAI since the merger, and the plan is a from-scratch foundation model shipping every month through the end of 2026.
Tomorrow we get to use it!
