Experiments with Subsetting Benchmark Suites

Benchmarks are one of the most popular tools to compare the performance of computing systems. Benchmark suites typically contain multiple benchmark programs with more or less the same properties. Hence the suite contains redundancy, which increases the cost of executing or simulating the benchmark suite without adding value. To limit simulation time, researchers frequently subset benchmark suites. However, correctly identifying a representative subset is of paramount importance to perform a trustworthy evaluation. This paper shows that subsetting a benchmark suite in such a way that representativeness of the suite is maintained is non-trivial. We show that a small randomly selected subset is not representative of the full benchmark suite. We discuss algorithms to subset the SPEC CPU 2000 benchmark suite and show that they provide more representative subsets than randomly selected subsets. However, the algorithms evaluated in this paper do not always compute representative subsets: the algorithms produce bad results for some subset sizes. In this sense, these algorithms are unreliable, as it remains necessary to validate the benchmark suite subset. We find one subsetting algorithm that is reliable. It is, however, uncertain whether this algorithm is also reliable under other circumstances