Intel Graphics: Windows 7 & Windows 8 vs. Ubuntu 13.04 & Fedora 18
When running Nexuiz, Fedora 18 with the GNOME Shell was performing about the same speed as the Ubuntu 13.04 Git results where the Intel Linux graphics driver state is nearly the same, and with the modern Unity/Compiz desktop overhead not carrying too much overhead like it has in the past. For this open-source OpenGL first person shooter, the Windows 7 SP1 performance was about the same as the earlier Windows 8 results.
With OpenArena 0.8.5 that is rather CPU-limited by today's hardware, Fedora 18 was still running in line with Ubuntu 13.04 Git. The results were close to Windows 8. Windows 7 SP1 for this ioqauek3-based game was slower than Microsoft Windows 8 on this Intel Ultrabook.