Supercomputers and Application Performance

Abstract

Before the advent of modern supercomputers, single processors were approaching the limit of improvement in operating frequency, and there was a memory wall problem. Even if the computing capacity of a single processor could be increased, the data supply capacity of the memory could not match the computing capacity. The increase in operating frequency also caused the problem, that is, power consumption increased faster than performance improvement. In other words, the limit of performance improvement of a single processor was becoming apparent. To solve these problems, parallel architectures, in which many single processors are connected by a communication mechanism, have been used. The two points, “programming conscious of parallelism” and “programming conscious of execution performance”, are very important for users, researchers, and programmers to make effective use of the present supercomputers equipped with tens of thousands of processors.