The are four complexes, virtually identical: AA, AB, AC and AD. All together, this HPCF features 7488 nodes:

There is an additional virtual complex, ECS, which is made from compute nodes of the 4 complexes. This is the one to be used by those users who don't have access to the full HPCF service.

The logic structure of one of the complexes would be as follows:

Main differences with the previous Cray XC40 system

The most notable change with respect to the previous Cray XC40 HPCF is in the processor architecture, from Intel to AMD. Although both implement the x86_64 instruction set, the latter has many more cores. 


Cray (CCA/CCB)Atos HPC2020 (AA/AB/AC/AD)
CPU ArchitectureIntel BroadwellAMD EPYC Rome

Core Frequency

2.1 GHz2.5 GHz (GPIL) / 2.25 GHz (compute)
Cores per node (HT)36 (72)128 (256)
Memory per node128 GiB512 GiB (GPIL) / 256 GiB (compute)
Fabric interconnectCray AriesMellanox HDR Infiniband - 100 Gbps (GPIL) / 200 Gbps (compute)
Operating SystemBased on SLES 11Based on RHEL 8
Batch systemPBS with ALPSSLURM
Parallel FilesystemLustreLustre
CompilersCray, GNU, IntelGNU, Intel, AOCC
MPICray MPICHIntel MPI, OpenMPI