This document provides an overview of the benchmark -HPGMG -for ranking large scale general purpose computers for use on the Top500 list [8]. We provide a rationale for the need for a replacement for the current metric HPL, some background of the Top500 list and the challenges of developing such a metric; we discuss our design philosophy and methodology, and an overview of the specification of the benchmark. The primary documentation with maintained details on the specification can be found at hpgmg.org and the Wiki and benchmark code itself can be found in the repository https://bitbucket.org/hpgmg/hpgmg.
SummaryThe High Performance Linpack (HPL) benchmark ) has been a successful metric for ranking high performance computing systems. HPL became a broadly accepted representative for application performance when it came to prominence in the 1990s, but over time has become less reflective of the system performance metrics that matter to contemporary science and engineering applications as lower complexity algorithms have been developed and required for extreme scale computing. We define a metric for ranking the worlds largest general purpose computers that maintains many of HPL's desirable qualities: a direct, non-iterative, solver (although only asymptotically exact) for systems of linear algebraic equations with a metric of equations solved per second (with a mapping to flops/s). We define a high performance geometric multigrid (HPGMG) benchmark that provides a more balanced exercise of machine capabilities, relative to application of interest in scientific computing, to provide a more accurate proxy for modern application requirements. HPGMG is composed of computations and data access patterns more commonly found in contemporary applications. Using HPGMG, we aim to create a benchmark for ranking systems that will promote system design improvements that are better aligned to real scientific application performance.
IntroductionThe High Performance Linpack () benchmark is the most widely recognized and discussed metric for ranking high performance computing systems. When HPL gained prominence as a performance metric in the early 1990s there was a strong correlation between its predictions of system rankings and the ranking that full-scale applications would realize. Computer system vendors pursued designs that would increase HPL performance, which would in turn improve overall application performance.HPL rankings of computer systems are no longer so strongly correlated to real application performance, especially for the broad set of HPC applications that analyze differential equations, which tend to have much stronger needs for high bandwidth and low latency, and tend to access data using irregular patterns. In fact, we have reached a point where designing a system for good HPL performance can actually lead to design choices that are wrong for the real application mix, or add unnecessary components or complexity to the system. Despite that, due to its long accumulated history, the Top500 list continues to...