The Taming of the Wolf - How to use the Ookami Cray Apollo 80 system and Fujitsu A64FX processors

The team running the Ookami HPE/Cray Apollo 80 system at Stony Brook University and from the University at Buffalo is holding a 6 hour workshop at the PEARC’23 conference. The workshop will focus on the characteristics of the Ookami testbed and the specific architecture of the Fujitsu A64FX FX700 processor.

Since October 2022, Ookami has also been an official ACCESS resource provider, as well as a Stony Brook resource. The Ookami scientific-computing and user-support team employs on a multi-modal outreach approach. This includes a closely-monitored Slack channel, twice-weekly office hours in which anyone can address any related issues, a ticketing system (both via Stony Brook and ACCESS), and by directly funding graduate students and working with them on science codes used by their research groups.

Our experience has shown that many users need a substantial amount of support, mainly because of the novel architecture of the A64FX processor, and unfamiliar toolchains. Many recipes that you might expect to work on standard x86 systems do not produce optimal results on this architecture, and achieving good performance often requires a more sophisticated and nuanced methodology. 

The focus of this workshop is thus to enable people to get a closer look at this interesting architecture, understand the challenges and opportunities it presents, become familiar with the software toolchains and performance analysis tools, and through hands-on access with experts in the room find ways to tackle and take advantage of them.