Computing · January 2026

Colossus 2 gigawatt cluster

The first AI training cluster to draw a gigawatt.

xAI brought Colossus 2 in Memphis online as the first 1-gigawatt AI training cluster, with 1.5 GW planned by April. It made the gigawatt the unit of AI build-outs.

See it in the living tree Wikipedia Source

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 2

Stargate compute build-out 2025
Nvidia Blackwell 2024

Related measurements

The dashed line marks when it first worked.

Training compute of notable AI models Source: Epoch AI, Notable AI Models (CC BY 4.0)

ML hardware FLOP/s per dollar Source: Epoch AI, ML hardware (CC BY 4.0)

Fastest supercomputer Latest: 1.81B GFLOP/s (2025) Source: Our World in Data