Why does Go perform badly on benchmark X?
One of Go’s design goals is to approach the performance of C for comparable programs, yet on some benchmarks it does quite poorly, including several in test/bench. The slowest depend on libraries for which versions of comparable performance are not available in Go. For instance, pidigits depends on a multi-precision math package, and the C versions, unlike Go’s, use GMP (which is written in optimized assembler). Benchmarks that depend on regular expressions (regex-dna, for instance) are essentially comparing Go’s stopgap regexp package to mature, highly optimized regular expression libraries like PCRE. Benchmark games are won by extensive tuning and the Go versions of most of the benchmarks need attention. If you measure comparable C and Go programs (reverse-complement is one example), you’ll see the two languages are much closer in raw performance than this suite would indicate. Still, there is room for improvement. The compilers are good but could be better, many libraries need major
