Musk Says Grok 4.8 Delay Came From Rewriting Software From Scratch in C

At a glance

Elon Musk said xAI's next AI model, Grok 4.8, was delayed because the team replaced its outside open-source tools with its own software. The model is expected to be released to a limited group this week.

Key points

1. 1

   The team dropped JAX and SGLang, which it used for AI training and serving, and built its own system.

2. 2

   The rewrite was mainly done in C, with some C++ mixed in.

3. 3

   Musk said training is finished and the model has entered reinforcement learning (training AI by rewarding good behavior), with scores starting to rise.

4. 4

   No speed-up figures have been measured outside the company, and no model card, benchmarks, or pricing have been published.

Why it matters

It shows that an AI model's release timing depends on the company's own software work, not just outside tools. The company also takes full responsibility for code that has not been checked by outside users.

Also reported by

• 솔루션뉴스머스크 "그록 4.8 며칠 안에 제한 공개…학습·추론 엔진 C/C++로 처음부터 다시 짰다"