$ module avail GCC
$ module load GCC
$ module load GCC
$ gcc -v
For the AMD Epyc processors which make up Comet, use the -march=znver5 compiler flag for GCC to enable detection and optimisation for the AMD Zen5 architecture of the compute node processors. As all nodes of Comet share the same Zen5 architecture, any binaries produced with these flags will run optimally across all node types:
Normal optimisation
# Note - this is the recommended optimisation level
gcc -march=znver5 -O2
Aggressive optimisation
gcc -march=znver5 -O3
Full optimisation
gcc -march=znver5 -Ofast
Additional options are discussed in this article from SUSE:
The znver5 option is only available in GCC 14 and higher. Please do not use older compilers with the Epyc processors as you will not get the most optimal binaries produced.
Requests for new/alternate versions of this package should be submitted via the NUIT ITService website using the HPC Software - Installation category.
Software requests will be collated, prioritized and submitted to our HPC support vendor.