Musk Says 2.5T-Parameter Grok 4.8 Finishes Pretraining This Week

Elon Musk and leaker markk say xAI's Grok 4.8 is a 2.5-trillion-parameter model trained on a new C++ stack, with pretraining finishing this week and reinforcement learning to follow.

2026-09-14 ~ 2026-09-14 · 3 related posts

• Musk says 2.5T-parameter Grok 4.8, trained on new C++ stack, finishes training this week — inductionheads · 2026-09-14
• Elon: Grok 4.8 is a 2.5T parameter model, starts RL after training this week — ns123abc · 2026-09-14
• Leaker claims Grok 4.8 will be a 2.5T-parameter monster, pretraining done this week — mark_k · 2026-09-14