AMD's Instinct MI300A APUs deliver a substantial performance improvement in HPC workloads versus traditional discrete GPUs.
The AMD Instinct MI300A is the realization of the "Exascale APU" platform that was laid out years ago. The idea was to package a high-performance GPU alongside a high-performance CPU on the same package which harnesses a unified memory pool. For HPC, these accelerators/co-processor designs provide higher performance per watt advantages but require a lot of porting, tuning, and maintaining applications with millions of lines of code which can be a bit complicated. However, it looks like researchers have used two popular programming models, OpenMP and OpenACC, to fully utilize AMD's next-gen APU juggernaut.
For this research paper, titled "Porting HPC Applications to AMD Instinct MI300A Using Unified Memory and OpenMP", the OpenFOAM framework is used, which is an open-source C++ library:
Since the AMD Instinct MI300A accelerator uses a unified HBM interface, it eliminates the need for data replication and does not require a programming distinction between the host and the device memory spaces. Furthermore, AMD's ROCm software suite provides additional optimizations that help combine all segments of the APU in one coherent and heterogeneous package. As a tiny bit of a recap on AMD's Instinct MI300A APUs: