Plasma-PEPSC D1.11 Updated Assessment of Developments and Revision of Scientific Challenge, Optimising Magnetically Confined Plasmas with GENE

In this deliverable, we describe the progress made for the gyrokinetic fusion turbulence code GENE-X since the last deliverable. The advancements are mainly threefold. First, we progressed on the GPU port of the code so that is can now be run fully on the GPU in a performant way. Second, the employed field solver library PARALLAX is now also fully ported to GPUs via the backend PAccX. Additional work has been invested in making the fieldsolver available on AMD GPUs and to employ a library solution instead of the self-written FGMRES-Multigrid solver. Third, the implementation of the block-structured grids reached a level of usability on the CPU which makes it possible to reduce the number of gridpoints by a factor of 4-8. It is not yet possible to combine all of the achievements, but with using the GPU code for GENE-X and the fieldsolver, we arrive at a FOM of around 20000 on 32 MI300A GPUs. The roadmap has been refined to further close the gap to the envisaged FOM of 6000.