ripgrep's introductory blog post[1] includes a perf comparison, which incorporates sift. But sift is too slow to include in several benchmarks. sift's achievement is its fast parallel directory traverser, coupled with Go's vectorized IndexByte[2] function for simple literals. In that case, it is quite fast, but as soon as you enter Go's regex engine, it's game over.

[1] - http://blog.burntsushi.net/ripgrep/

[2] - https://golang.org/pkg/bytes/#IndexByte