Mac OS X 10.8 vs. Ubuntu 12.04 LTS Performance
Ubuntu Linux with its default EXT4 file-system was faster for the PostMark mail server benchmark than Mac OS X 10.8 that's still with a Journaled HFS+ file-system.
For the Compile Bench test that does involve some disk workloads, the performance was close to the same between software platforms.
However, for other Compile Bench results, Ubuntu fell behind Apple's software.