Keynote: Performance Portability for Next-Generation Heterogeneous Systems
ISC 2023 IXPUG Workshop: Communication, I/O, and Storage at Scale on Next-Generation Platforms - Scalable Infrastructures
Date: 25 May 2023 at 08:00
Location: In-person at ISC 2023, Hamburg, Germany
There is a huge diversity in the processors used to power the leading supercomputers. Despite their differences in how they need to be programmed, these processors lie on a spectrum of design. GPU-accelerated systems are optimised for throughput calculations providing high memory bandwidth; CPUs provide deep and complex cache hierarchies to improve memory latency; and both use vector units to bolster compute performance. Competitive processors are available from a multitude of vendors, with each becoming more heterogeneous with every generation. This gives us as a HPC community a choice, but how do we write our applications to make the most of this opportunity?
Our high-performance applications must be written to embrace the full ecosystem of supercomputer design. They need to take advantage of the hierarchy of concurrency on offer, and utilise the whole processor. And writing these applications must be productive because HPC software outlives any one system. Our applications need to address the “Three Ps” and be Performance Portable and Productive.
This talk will highlight the opportunities this variety of heterogeneous architectures brings to applications, and how application performance and portability can be rigorously measured and compared across diverse architectures. It will share a strategy for writing performance portable applications and present the roles that ISO languages C++ and Fortran, as well as parallel programming models and abstractions such as OpenMP, SYCL and Kokkos play in the ever changing heterogeneous landscape.