The few times I've dealt with MIPS architecture, it has seemed like software isn't really that well optimised for it. It works. Just... not as fast as it can do, e.g. zlib.

There are some forked versions of the main zlib library with MIPS optimisations in them that really fly, but nothing that has ever hit upstream, and I'm not crazy enough to want to rely on unpatched/unsupported code like that.