Compression is generally CPU bound for most of the typical algorithms (LZMA, zlib/deflate) unless your drive is very very slow (<10 MB/s). There are some quite

Compression is generally CPU bound for most of the typical algorithms (LZMA, zlib/deflate) unless your drive is very very slow (<10 MB/s). There are some quite fast algorithms where this could make sense, basically using something like LZ4 as a proxy for compress-ability. This is the approach some tools use when you tell them to "compress, but only if it makes sense".