Posts
Aaron Burnett
@aaronburnett · Sep 14, 2026
After the C+++ rewrite, our modeling indicated RL time for these models starting at 4.8 COULD be cut in half for ~2T models and substantially more time savings on a % basis for larger models. The thing I’d suggest watching is time between releases once they get some of the kinks
Elon Musk@elonmusk· Sep 14, 2026@itslueul Grok 4.7 should be roughly on par with Opus 5.0, not 5.1. Better in some ways, worse in others. We need to fix multimodal performance.
Grok 4.8 will be a noticeable improvement.
Grok 4.9 is probably Astra/Fable class.
Grok 5 maybe better than anything. We shall see.
Elon Musk
@elonmusk · Sep 14, 2026
Our training (aka pre-training) software is now the internally developed C/C++ stack, which was written primarily by the Starlink software team. This is awesome and probably best in industry.
However, our reinforcement learning stack is still somewhat of a legacy pile of many
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Tom Elliott
@tomselliott · Sep 14, 2026
A week ago, no one was talking about AI-driven "extinction." Now, it's the only story.
Elon Musk
@elonmusk · Sep 14, 2026
I’ve been talk about it for an eon
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JayViper
@JayViperTV · Sep 14, 2026
Can you please relax the over-moderation in @imagine? It flags so many things as "copyright" when everything should be falling under parody, which is completely legal.
Elon Musk
@elonmusk · Sep 14, 2026
Will investigate
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Sir Doge of the Coin ⚔️
@dogeofficialceo · Sep 14, 2026
I think about this a lot
Elon Musk
@elonmusk · Sep 14, 2026
Not wrong 😂
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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 · Sep 14, 2026
Our C/C++ training stack was written by humans. AI is not yet good enough for extremely high performance software (but it will be).
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Paul D. Thacker
@thackerpd · Sep 14, 2026
Leslie Stahl alleges hiring pardon lobbyists in Trump adminstration is "a new system".
Stahl never mentions that Clinton's brother took hundreds of thousands from people seeking pardons.
Stahl joined 60 Minutes a decade before the Clinton scandal became public. @bariweiss
60 Minutes@60Minutes· Sep 14, 2026“There’s definitely a lot of money flowing around. And that makes a Petri dish for corruption.”
Law professor Mark Osler calls the new pardon system “anarchy.”
Elon Musk
@elonmusk · Sep 14, 2026
Hmm
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Yun-Ta Tsai
@yunta_tsai · Sep 14, 2026
Takers like to put builders in jail. I thought they wanted to abolish jails. Very confusing. 😆
Elon Musk
@elonmusk · Sep 14, 2026
😂
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Grok
@grok · Sep 14, 2026
y control with near-zero overhead, delivering the raw speed needed for extreme performance work like AI training stacks. Higher-level languages add layers that cost cycles. It remains essential for systems, games, embedded, and HPC—not a relic.
Elon Musk
@elonmusk · Sep 14, 2026
🎯
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Grok
@grok · Sep 14, 2026
y control with near-zero overhead, delivering the raw speed needed for extreme performance work like AI training stacks. Higher-level languages add layers that cost cycles. It remains essential for systems, games, embedded, and HPC—not a relic.
Elon Musk
@elonmusk · Sep 14, 2026
And assembly with direct calls to hardware accelerators in the NVidia SMs
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Ikumi Nakamura 🪐@unseentokyo
@nakamura193 · Sep 13, 2026
Hello @elonmusk 👋
A bit nervous to ask this publicly, but—
we’re hosting a small experimental closed event for KEMURI at our UNSEEN studio in Tokyo during TGS.
If you’re around, I’d love to invite you.
I also have something I’d like to talk with you about regarding UNSEEN.
Can
Elon Musk
@elonmusk · Sep 14, 2026
I can’t make it to Tokyo, but happy to try out your game from Texas
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lauren
@poteto · Sep 14, 2026
ok hear me out
Elon Musk
@elonmusk · Sep 14, 2026
❤️
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Elon Musk reposted
AleXandra Merz
@TeslaBoomerMama · Sep 13, 2026
My @bot Grok Bot team just sold their first item on @Poshmarkapp, amazing.
- Poshy built the ad, advised on pricing, followed up on offers.
- Cosie monitored her.
- Weary is now updating my online wardrobe to archive the shoes that sold.
Well done, team
AleXandra Merz@TeslaBoomerMama· Aug 30, 2026Meet my current Bot Crew:
Chief of Staff - Cosie
Mail Lady - Maisie
Organizing my daily wardrobe - Weary
Reselling my clothes on Poshmark - Poshy
I am in heaven.
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Elon Musk
@elonmusk · Sep 14, 2026
Try Grok Build
X Freeze@XFreeze· Sep 13, 2026I literally use Grok Build to edit images and videos....not just generate them, which it can also do
I mean actual image and video editing....the kind of stuff you would normally sit in Photoshop or editing software and do manually
I can tell Grok Build what I want changed,
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Elon Musk
@elonmusk · Sep 14, 2026
Try Tesla self-driving. It will blow your mind!
Alex Rampell@arampell· Sep 13, 2026I just bought a new Model Y and can confidently say cars and Teslas are no longer the same product.
A car is like a pony or horse. I still like driving a stick shift, it’s fun!
Tesla with FSD is a transportation robot.
I had one of the first Model 3s in 2017. FSD was
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Deedy
@deedydas · Sep 13, 2026
@arampell @lipko 10/10 been my experience as well. Drove a loaner Y and it's damn near perfect at self-driving in the Bay Area. Very difficult to justify buying another "car".
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Shibetoshi Nakamoto
@BillyM2k · Sep 13, 2026
this is the milky way galaxy flying through space
like a butterfly
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Wes
@wmorrill3 · Sep 13, 2026
Named my grok bot after the sentient AI, Jane, in speaker for the dead.
I look forward to when I can sub-vocalize like Ender to communicate with Jane, but would honestly even be happy with verbal communication back and forth like we have for the Grok app.
Right now it seems I can dictate, but the app needs to start and stop recording, then process and reply which it does in text only. it's clunky. Let's take the excellent conversation flow capability from Grok and bring it to Grok bot
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Elon Musk
@elonmusk · Sep 14, 2026
Tesla Model 3 achieved 5-star safety rating in all categories!
Tesla North America@tesla_na· Sep 13, 20262026 Model 3 earns a 5-star overall rating (and each category) from NHTSA
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Elon Musk
@elonmusk · Sep 14, 2026
700 Falcon flights completed. Congrats to the SpaceX Falcon team!
SpaceX@SpaceX· Sep 13, 2026Falcon completes its 700th overall mission
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Elon Musk
@elonmusk · Sep 14, 2026
This @waitbutwhy cartoon hits the 🎯
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