El Capitan is a Cray EX255a/MI300A supercomputer at LLNL that debuted at the #1 position on the November 2024 Top500 list with an HPL score of 1.742 EFLOPS. The HPL run took 6,306 seconds, or 1.75 hours.

System overview

El Capitan has:1

  • 11,136 Cray EX255a compute nodes
  • 44,544 AMD MI300A APUs total
  • 87 cabinets
  • 696 Rabbit blades (8 per cabinet)2
  • 34.8 MW peak, 30 MW running HPL2

El Capitan uses a Slingshot-11 fabric in a dragonfly topology.

Node architecture

Each Cray EX255a node has:

  • 4x AMD MI300A APUs (see Specifications)
  • 512 GB HBM3 using 8-high stacks
  • Fully interconnected sockets

Storage subsystem

El Capitan features two storage subsystems:2

  • 696 Rabbit blades, providing near-node-local storage on the Slingshot fabric
  • A global Lustre file system named Merced

Footnotes

  1. “El Capitan” Supercomputer Blazes The Trail for Converged CPU-GPU Compute

  2. TOP500 Supercomputers – SC24 Schedule 2 3