The supercomputer xAI built in a former Electrolux factory in Southwest Memphis, run since the merger by SpaceXAI and then SpaceXSI. Colossus 2, its second, has its compute in Memphis and its power across the state line in Southaven, Mississippi. Chapter 4.
From The AI Compute Race. Read the book
Defined in Chapter 4 — One Rack.
Where the book uses it
- Chapter 4 — One Rack
How a datacenter is actually built, from a converted factory in Memphis to a greenfield campus in Texas, and what the clock from first ground to first power really measures.
Where the record uses it
- Campus Colossus 2
- Campus Colossus 1
- Scorecard indicator Largest evidenced operating site
- Person Musk, Elon
Sources that use it
- Anthropic, “Higher usage limits for Claude and a compute deal with SpaceX,” 6 May 2026 (the page lists its compute agreements, among them “A 5 GW agreement with Google and Broadcom, which will begin coming online in 2027”, three weeks before the Series H release of 28 May repeated the figure; also “An up to 5 gigawatt (GW) agreement with Amazon, which includes nearly 1 GW of new capacity by the end of 2026”, and the SpaceX agreement for “all of the compute capacity at their Colossus 1 data center”, “more than 300 megawatts of new capacity (over 220,000 NVIDIA GPUs) within the month”; in the record) In the Sources
- Anthropic, “Series H,” 28 May 2026 ($65 billion at $965 billion post-money, MGX a significant investor; “We signed agreements with Amazon for up to five gigawatts of new capacity, with Google and Broadcom for five gigawatts of next-generation TPU capacity, and with SpaceX for access to GPU capacity in Colossus 1 and Colossus 2”). In the Sources
- Elon Musk, post on X announcing the Colossus milestone, 2 September 2024 (“This weekend, the @xAI team brought our Colossus 100k H100 training cluster online. From start to finish, it was done in 122 days.”). In the Sources
- Patrick Kennedy, ServeTheHome, “Inside the 100K GPU xAI Colossus Cluster that Supermicro Helped Build for Elon Musk,” 28 October 2024, reprinted by Supermicro as a case study, December 2024 (64 H100s per rack, eight racks per 512-GPU block, one coolant loop and CDU per rack, nine 400 GbE links per server; cabling crews and Megapacks observed on site; “the initial cluster of four 25,000 GPU data halls is up and running for around 100,000 GPUs at the time of our visit”; on the power work seen on the visit: “huge power cables”; on the fabric: “Many supercomputer networks use InfiniBand or other technologies, but this is Ethernet. Ethernet means it can scale.”; on the Megapacks: “the millisecond spikes and drops in power were stressful enough that putting the Tesla Megapacks in the middle to help buffer those spikes in power helped make the entire installation more reliable”; sponsored by Supermicro, the article says, and made with “special approval by Elon Musk and his team”) In the Sources
- xAI, “Colossus: The World’s Largest AI Supercomputer,” accessed 29 August 2026 and, by Wayback capture, 9 September 2026 (the page gives 122 days, “Then we doubled it in 92 days to 200k GPUs” and 276 days from groundbreak, and prints 200,000 over “H100 GPUs in a single interconnected cluster”; its counter further down is an animation that the page’s script, as served on 30 September 2026, runs from 180 to 200 once half its tile is in view, so the 180,000 read in the unscrolled markup at the close was its first frame, and the page scrolled into view on 12 October 2026 showed 200K; the page prints no 100,000 and no Megapack count; the script counts its days from groundbreak from an origin it writes as 1 May 2024, the first of a month like each of its seven milestones, and of those milestones, drawn only when a reader presses a point on the timeline, the one of 1 January 2025 reads “Training finished with 80K+ GPUs. 122 days from groundbreak to training.” and the one titled “Training begins”, of 1 September 2024, reads “42K-GPU job with elastic training, running across 4 data halls.”; the timeline’s own data dates the doubling 1 February 2025, its axis ending Feb 2025, and 1 May 2024 to 1 February 2025 is the page’s 276 days, though the page’s script prints that date in the reader’s own time zone, so a browser west of UTC shows the milestone as “January 2025”; re-read through Browserbase on 27 September 2026, a plain fetch refused by Cloudflare: the same 122, 92 and 276 days, the axis still ending Feb 2025; the milestone card showed the earlier month on a live read of 12 September 2026 and on that Browserbase read, and the later month on the Wayback capture of 20 August 2026; the page’s timeline script read whole on 30 September 2026; the page’s lead: “Built in 122 days — outpacing every estimate — Colossus was the most powerful AI training system yet”). In the Sources
And 34 more: search the Sources.
Related terms
From the glossary of The AI Compute Race.
How to cite this page
Dryburgh, Lee S. “Colossus.” In The AI Compute Race. DRYBURGH. https://dryburgh.com/vol1/glossary/colossus (accessed 2026-11-01).
BibTeX
@misc{dryburgh-colossus-2026,
author = {Dryburgh, Lee S.},
title = {{Colossus}},
howpublished = {In \emph{The AI Compute Race}, DRYBURGH},
year = {2026},
url = {https://dryburgh.com/vol1/glossary/colossus},
note = {Accessed 2026-11-01}
}