The LAME MP3 encoding was nearly 20% faster under Debian GNU/Linux than Debian GNU/Hurd.
The results for the Himeno computational benchmark were nearly identical between the two Debian Wheezy variants.
There was only a handful of tests that could be successfully run under Debian GNU/Hurd and in those results the numbers were generally close, though Debian GNU/Linux was running about 4% faster in some and with the MP3 encoding the Linux OS was nearly 20% faster. Debian GNU/Hurd is an interesting project but for now its support is still in shambles, the hardware support is vastly outdated, and there is also no SMP support at this time. Regardless, it will be interesting to see how Debian GNU/Hurd turns out for the 7.0 Wheezy milestone.