Elon Musk: Grok 4.8 is in RL and rebuilt from scratch in C/C++
Elon Musk just revealed that Grok 4.8 has finished pre-training and entered reinforcement learning, with a soft rollout to some Grok Bot users slated for later this week. The team ditched JAX and SGLang to rewrite their entire RL and inference stack in C/C++. Musk noted that 4.8 will bear no resemblance to 4.7 as evaluation benchmarks climb.