xAI Colossus
Memphis, Tennessee, US · operating · operated for xAI
xAI's GPU supercluster for training Grok, built inside a former Electrolux appliance factory in south Memphis and famous for its build speed: the first 100,000 GPUs came online in 122 days. A second campus (Colossus 2) is under construction nearby.
Compute Atlas, the sister dataset on supercomputer and AI-cluster supply chains, has the component-by-component record for this campus: xAI Colossus (system) · xAI Colossus 2 (system).
What's documented
- 100,000 Nvidia H100 GPUs brought online in 122 days, with training starting 19 days after the first rack was installed (announced October 2024). [source]
- Networking is Nvidia Spectrum-X Ethernet — Spectrum SN5600 switches with 800Gb/s ports and BlueField-3 SuperNICs. [source]
- Expanded to roughly 200,000 GPUs within a further 92 days; by December 2025 reported at 150,000 H100 + 50,000 H200 + 30,000 GB200. [source]
- Liquid-cooled from inception using Supermicro 4U liquid-cooled racks (64 GPUs per rack); power draw around 250 MW, up from an initial 150 MW substation. [source]
- In March 2026 Mississippi regulators permitted 41 permanent gas turbines at the Southaven site powering Colossus 2, replacing 27 previously unpermitted units; the NAACP announced intent to sue over the earlier unpermitted turbines. [source]
- Tesla Megapack batteries buffer the site — roughly 156 at the original site plus 168 more announced for Colossus 2 in May 2025. [source]
Suppliers reported inside
| Company | What | Source |
|---|---|---|
| Supermicro | liquid-cooled GPU racks (reported as more than half of them) | source |
| Dell | AI-optimized servers (tens of thousands, reported) | source |
| Nvidia | H100/H200/GB200 GPUs, Spectrum-X switching, BlueField-3 SuperNICs | source |
| Tesla | Megapack battery storage | source |
Placements come from the cited reporting, not operator disclosures, unless a source says otherwise.
The generic bill of materials
Whatever the vendor list, a facility like this contains the same part categories:rack-scale systems, direct-to-chip cold plates, coolant distribution units, large power transformers (345–765 kV) & substations, UPS (static, modular, rotary/DRUPS) & UPS power semis, backup generation: gensets, fuel systems, HVO, chillers & compressors — the full set is in the scales matrix.