Lucata Pathfinder FAQs

This page details answers to some commonly asked questions about the Lucata Pathfinder system.

What are the detailed specs for GT’s Pathfinder systems?

GT currently hosts a two-chassis Pathfinder system which has 16 nodes in total with 8 in each chassis. The nodes are connected directly via RapidIO links.

  • Stationary cores per node/chassis: 1/8
  • Memory-side processors per node/chassis: 8/64
  • Memory channel width: 16 bit
  • Memory per node/chassis: 64 GB/512 GB
  • Gossamer Cores or Lucata Compute Elements (LCE) per node/chassis: 24/192
  • LCE clock speed: ~220 MHz (may be slightly higher/lower)
  • Maximum number of concurrent threads per node/chassis: 1536/12,288 (additional spawned threads sit in the run queue)
  • Power usage per chassis: ~2KW max although likely lower in practice
  • System node CPUs are PowerPC e6500 T2080 CPUs with 8 cores, running at 1.8 GHz
  • Nodes inside a chassis are connected to 6 internal switches that each have 12 ports
    • 4 ports per switch can be used to connect to other chassis while other ports connect to all 8 nodes in an endpoint star formation
    • Within a chassis each node should be accessible within 1 switch hop; 2 chassis requires 2 switch hops
    • Note that GT does not have a rack-mounted switch that would further scale the network.