The are four complexes, virtually identical: AA, AB, AC and AD. All together, this HPCF features 7488 nodes:
- 7020 compute nodes, for parallel jobs
- 448 GPIL (General Purpose and Interactive Login) nodes, which are devised to integrate the interactive and post-processing work that coming from older platforms such as the Cray HPCF, ECGATE and Linux Clusters.
Main differences with the previous Cray XC40 system
The most notorious change in respect to the previous is on 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 Architecture | Intel Broadwell | AMD EPYC Rome |
Core Frequency | 2.1 GHz | 2.5 GHz (GPIL) / 2.25 GHz (compute) |
| Cores per node (HT) | 36 (72) | 128 (256) |
| Memory per node | 128 GiB | 512 GiB (GPIL) / 256 GiB (compute) |
| Fabric interconnect | Cray Aries | Mellanox HDR Infiniband - 100 Gbps (GPIL) / 200 Gbps (compute) |
| Operating System | Based on SLES 11 | Based on RHEL 8 |
| Batch system | PBS with ALPS | SLURM |
| Parallel Filesystem | Lustre | Lustre |
| Compilers | Cray, GNU, Intel | GNU, Intel, AOCC |
| MPI | Cray MPICH | Intel MPI, OpenMPI |