Patrick C Toulme
@PatrickToulme · Sep 14, 2026
The MFU on this full C++ stack is part of the reason xAI is churning out so many models. I would bet their stack is full of inline PTX and most likely completely AI generated by stronger models like GPT and Claude Fable.
The need for higher level frameworks for prod training is
NIK@ns123abc· Sep 14, 2026🚨 JUST IN: Elon says Grok 4.8 is a 2.5T parameter model that finishes training on SpaceXAI's new C++ stack this week and then starts RL
Elon Musk
@elonmusk
Our C/C++ training stack was written by humans. AI is not yet good enough for extremely high performance software (but it will be).
04:56 PM · September 14, 2026 · 1.2M views
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