Phase 2 - XC50 ARM

Cray XC50 cabinet, codenamed XCI, containing 10’000 ARM cores, available since November 2018.

  • Cavium ThunderX2 ARM v8.1
    • 16nm FinFET CPU @ 2.1GHz
    • 4-way simultaneous multi-threading
    • 128-bit SIMD “NEON”
    • 32KB L1 instruction & data cache, 256KB L2 per core, 32MB distributed L3 cache
    • 256GB RAM across 8 DDR4 DIMMs @ 2400MHz
    • Cray Aries interconnect in dragonfly topology operating at 14Gbps~
  • Cray Linux Environment 7 (Suse SLES 15)
    • Cray Programming Environment with CCE 8.7.9

Both Phase 1 & 2 use the same authentication system and Lustre filesystem.

Queues

Work is submitted via the arm queue.

Software

  • GCC (7.3, loaded by PrgEnv-cray)
  • R (3.3, loaded by cray-R)
  • Python 2.7 (loaded by cray-python/2.7)
  • Python 3.6 (loaded by cray-python/3.6

Caveats

The default python version on login nodes is a system-bundled version, be sure to load a version of cray-python before running code.

Known errors

Some Cray compilers will emit this error message:

No supported cpu target is set, CRAY_CPU_TARGET=aarch64 will be used. Load a valid targeting module or set CRAY_CPU_TARGET

To silence this message and to ensure the correct CPU optimisations are applied, run the following before using the compiler:

module load craype-arm-thunderx2

Available modules

PrgEnv-cray
PrgEnv-allinea
PrgEnv-gnu
cray-python
cray-python
cray-R
gcc
craype-aarch64
craype-hugepages1G
craype-hugepages2M
craype-hugepages8M
craype-hugepages32M
craype-hugepages128M
craype-hugepages512M
craype-network-none
craype-arm-thunderx2
craype-hugepages2G
craype-hugepages4M
craype-hugepages16M
craype-hugepages64M
craype-hugepages256M
craype-network-aries
perftools
perftools-lite
perftools-lite-events
perftools-lite-gpu
perftools-lite-hbm
perftools-lite-loops
perftools-nwpc
perftools-preload