Musk Says Grok 4.8 Will Have 2.5 Trillion Parameters, Training Done This Week

xAI CEO Elon Musk said on X that Grok 4.8 will be an AI model with 2.5 trillion parameters, trained using a new C++ software stack.

Musk said Grok 4.8 will finish training this week and start reinforcement learning. He previously said Grok 4.7 would launch on September 12, but later noted it might take a few more days.

The delay may be due to overly heavy response-length penalties in reinforcement learning, causing the model to give up on hard tasks too early and fail to check its own work carefully.