Hackathon II - MPI

[arporter]

This Issue provides a place to capture planning (and possibly results) for the 2nd NEMO GPU hackathon. The intention is for this hackathon to focus on getting NEMO running on multiple GPUs using MPI.

• [ ] Hardware. STFC's workstation has 2 GPUs. Isambard hardware configuration to be checked.
• [ ] NEMO configuration. Currently we use ORCA1-SI3-G08 but we will need a larger domain when running on multiple GPUs.
• [ ] Use PSyclone to process existing configuration with MPI enabled. Validate.
• [ ] Investigate performance of this 'vanilla' MPI version with ORCA1 configuration.
• [ ] Optimise using [GPUDirect?]
• [ ] Investigate performance on larger domain.
• [ ] Investigate performance on Ampere??

[waynegaudin]

I'm looking into cloud resources for access to A100s. These are not in place yet but they should be soon.