The way supercomputer power is measured is about to change. Since 1993, the much-celebrated bi-annual TOP500 list is compiled using Jack Dongarra’s benchmark system, called Linpack. It is the most widely recognized and discussed metric for ranking HPC systems.
But Dongarra says Linpack hasn’t kept pace with supercomputing needs and must be updated.
Linpack rankings of computer systems are no longer so strongly correlated to real application performance,” Dongarra said.
Dongarra and his colleague Michael Heroux from Sandia National Laboratories in Albuquerque, New Mexico, are developing a new benchmark that is expected to be released in time for the next TOP500 list release in November. The new benchmark, called the High Performance Conjugate Gradient HPCG, should better correlate to computation and data access patterns found in many applications today. This could improve the high performance community, because some of today’s supercomputers are being designed to gain a high score for the TOP500 list than to meet real-life demands.
So what is HPCG? As a preconditioned conjugate gradient (PCG) benchmark, it uses a local symmetric Gauss-Seidel preconditioner. That’s a mouthful, but you can download Sandia’s paper on HPCG to learn more.
We have reached a point where designing a system for good Linpack performance can actually lead to design choices that are wrong for the real application mix, or add unnecessary components or complexity to the system,” said Dongarra. “The hope is that this new rating system will drive computer system design and implementation in directions that will better impact performance improvement for real applications.”
Dongarra also expects the new benchmark to adapt to emerging trends, unlike its predecessor.
Linpack will not be laid to rest, however. Instead, HPCG will serve as an alternative ranking of the TOP500 list, allowing a re-ranking of the systems on the list to “real” applications. Read the Full Story.