Elon Musk spent the early hours of Tuesday explaining why Grok 4.8 ran late: his team threw out the open-source tools it trained and served Grok with and wrote its own, in his words “C with a little C++, but not too much.” This edition covers 6:53 a.m. PST Monday, Nov. 9, to 6:53 a.m. PST Tuesday, Nov. 10. It quotes his posts with a link to each, pairs claims with other sources where the desk found them, and follows Jacob and Isaac’s working topic order from their Oct. 31 episode timestamps (episode index) and their Nov. 6 episode (YouTube); the desk found no newer episode to recheck the order on Tuesday. Tesla opens, as in that order, and the Grok 4.8 thread gets the deep dive because it drew the most news coverage. The desk found no new interview or public appearance in the window. Video follows at the end.

Highlights. Grok 4.8 sits in reinforcement learning on a rewritten C/C++ stack, with a soft rollout to Grok Bot users planned for later this week, he wrote (). He credited Starlink’s software for that stack (). And he greeted Tesla’s solar factory near Houston with “Project Crystal Sun” ().

Topic by topic

1. Tesla. Besides the Crystal Sun quote, Teslarati and Samaa TV both report Tesla’s filings: about $10.1 billion, commercial production targeted for the first quarter of 2029, and about 9,712 permanent jobs by 2033 (Teslarati; Samaa TV). Samaa TV adds that Tesla’s application also named a possible site outside Texas (Samaa TV). Replying to @herbertong’s post on a report that Tesla cut the LPDDR6 memory on its AI6 chip for Optimus from 216GB to 144GB, he wrote “Memory bandwidth was held constant though” (; ); China Flash Market, the report’s source, says the same about bandwidth and calls the change a design decision not yet proven in mass production (China Flash Market). Answering Palmer Luckey on ride-hailing economics, he wrote, “Cybercab will do a majority of all passenger miles in any jurisdiction where it is not prohibited by law” (; ). He reposted @SawyerMerritt’s clip of Jay Leno trying FSD (Supervised) for the first time () and @XFreeze’s clip of Tesla vice president Lars Moravy calling Tesla “the largest selling luxury vehicle in the world now” (). He answered @stevenmarkryan’s video on his wealth with “Well, if they didn’t like $1T, they’re REALLY gonna hate $10T 😂” () and replied “Exactly” to @TheCaptainEli’s long post arguing that he co-founded Tesla ().

2. SpaceX and Starlink. He reposted three @cb_doge posts on Starlink in remote places: five people stranded in Kazakhstan’s snowy mountains (), a family trapped by snow near Bariloche, Argentina (), and 196 Vietnamese locations that, citing Vietnam’s science ministry, got service by Nov. 1 (). He reposted @Starlink’s note on Wi-Fi aboard Brussels Airlines (). He quoted @teslaownersSV’s clip of SpaceX President Gwynne Shotwell saying “That’s the man (@elonmusk I’ve worked for for 24 years. I love him.” with “Gwynne is great” (), about 2.1 million views, and reposted @EvaFox’s clip on how SpaceX began (). He also reposted @KatieMiller’s clip of Memphis Mayor Paul Young saying data-center taxes reached “$54 million” this year (); in @firesidealpha’s transcript of the same answer, which he also reposted, Young adds that the city wants to talk about data centers “in a balanced way” and names environmental, noise and traffic concerns ().

3. Grok Bot and xAI. The Grok 4.8 thread gets its own deep dive below. He quoted @SawyerMerritt’s post on remarks by SpaceX launch vice president Kiko Dontchev with one word, “Grok” (). Ars Technica, the post’s linked source, quotes Dontchev at the UP.Summit conference: “humans are about 94 percent perfect (at) finding a piece of it. Grok analyzing the same video is 99.9 percent perfect,” about spotting foreign object debris in aerospace parts, and “fundamentally we are an infrastructure company at this point” (Ars Technica). He reposted @bot’s weekly-limit reset (); @BrianRoemmele’s post on a Grok Bot he built that turns YouTube videos and podcasts into a weekly magazine (), whose public page says a third-party user, not SpaceXSI, made it (x.ai bot page); and @mattyp’s note “I’ll be using @bot to get aggregate feedback to the team” ().

4. Artificial intelligence. Quoting @jamesdouma’s worry that Anthropic could end up “building the super-intelligence that they fear,” he wrote “The most entertaining outcome is the most likely, especially if ironic” (), about 2.5 million views. He reposted @0xMiraxq’s transcript of an older interview in which he walks through battery costs “from first principles, not by analogy” (); the post gives no date for the interview.

5. U.S. politics. He reposted @NathanielSami’s post quoting his earlier reply to a Wall Street Journal story on Texas Democrats: “SpaceX and Tesla have prospered in Texas, because we were not constantly operating under an oppressive and extractive state government” (). He reposted @KatieMiller’s claim that his companies employ “nearly 160,000” people directly (), @EndWokeness’s list of California presidential margins tied to immigration (), and replied “System sure doesn’t seem to be working for the people” to @cfdownes_ (). He answered @EndWokeness’s claim about media coverage of a killing with “!!” (). The desk did not verify the job, margin or media-coverage claims.

6. Europe and the world. Russell Brand drew five posts. On Nov. 9 Mr Justice Bennathan sentenced Brand to a total of 10 years and six months, nine years of it for one rape and concurrent terms for three sexual assaults, according to the judge’s published sentencing remarks (Courts and Tribunals Judiciary) and IBTimes UK (IBTimes UK). Musk reposted two @TheJadeWarwick posts calling the sentence unjust (; ), @JTLonsdale’s post calling the UK justice system “an utter joke” () and @MegynKellyShow’s clip calling the case a “political WITCH HUNT” (). He replied “Wow” to a post comparing Brand’s term with another case () and “Horrific” to @CompositeGuy_’s post on Telford abuse cases, attaching a Grok chat link (; Grok share); the desk did not verify that post’s figures. His one-word “Unjust” reply, which TMZ and IBTimes UK cover, came before this window (TMZ). He also reposted @ricwe123 on German immigration () and replied “😂” to a French post joking about Nvidia chief Jensen Huang and Chinese spies ().

7. Culture, health and jokes. He replied “Interesting” to cardiologist Eric Topol’s post on two trials of the GLP-1 drug retatrutide for knee osteoarthritis (; ), “😂” to @DogecoinNorway (), and reposted @beffjezos wishing for a Shinkansen-style train between San Francisco and Los Angeles ().

Deep dive: Grok 4.8 and the new stack

The full Grok 4.8 post runs six sentences. After the rewrite and the pre-training news, he wrote: “Lot of cleanup was needed on the SFT data to get that mostly right.” He closed: “Grok 4.8 will bear no resemblance to 4.7 (thankfully). It is not yet incredible, but, this time, the foundations are built right, so I expect it to evolve to be something special” (). SFT stands for supervised fine-tuning; RL for reinforcement learning. PANews and The News (Pakistan) carried the same post (PANews; The News).

Follow-up replies filled in the build. Asked by @tetsuoai about the language, he wrote “C with a little C++, but not too much” (), then “At SpaceX, we write our own headers and calculate our own time (includes leap seconds). Not many people will know what this means, but those that do will appreciate it,” adding that the new Grok “AI/SI training and inference stack is derived from incredible of work done by amazing engineers to create Starlink” (sic; ), about 740,000 views. He added “(There’s even some assembly)” and “One day, super intelligence will write a better software stack, but that day has not yet come” (). Asked why not Rust, he replied “Real men manage their own memory” (). He also marked “💯” a reply suggesting JAX users eventually rewrite their own kernels anyway ().

The dates matter to Grok Bot users. CellCog reports that on Sept. 13 he called Grok 4.8 “a 2.5T model trained with our new C++ software stack” that would finish training that week, and that his dates “have slipped on every Grok 4 release so far”; it lists Grok 4.7’s release as Sept. 21 (CellCog). The Tuesday post names no day, cohort size, price or benchmark. Asked how 4.8 compares with Anthropic’s Opus 5.5, he answered “Not as good,” then forecast that Grok 5 “should exceed Opus 5.5” in “2 or 3 months” (). He reposted two @XFreeze summaries of the thread (; ).