OS X 10.10 vs. Ubuntu 14.10 vs. Fedora 21 vs. openSUSE Factory
OpenSUSE in its rolling-release state led over Ubuntu 14.10 and Fedora 21 too. All three Linux distributions with the Intel Mesa OpenGL driver were much faster than OS X 10.10 Yosemite for the Intel HD Graphics 5000 hardware found on the 2013 MacBook Air.
In the CPU bound tests, the Linux distributions were leading, likely due to their use of modern GCC by default compared to LLVM/Clang with Xcode. Again, in the earlier OS X 10.10 vs. Ubuntu 14.10 comparison are Clang results on Ubuntu side-by-side with GCC.
OpenSUSE is still shipping GCC 4.8 rather than GCC 4.9, which for some tests does mean a performance difference between the three Linux distributions that otherwise are using close to the same package versions.