Immediately with Nexuiz we see Apple's Mac OS X operating system and their in-house Intel driver running steadily faster than under Ubuntu 10.10 (there's no results for Ubuntu 11.04 Alpha 2 as this test was broken with that Ubuntu Natty development build). Neither operating system would be considered to provide a playable frame-rate on the Mac Mini when using the Phoronix Test Suite's Nexuiz profile settings of high, which includes the use of GLSL and other graphical features that push down the i945 graphics. With Mac OS X, we see an odd spike in performance at the 1400 x 1050 and 1680 x 1050 resolutions, but is somewhat similar to what we have encountered in the past where the graphics performance can be eccentric when not running at the native resolution. For those unfamiliar with the Phoronix Test Suite, each test at each resolution is run multiple times to ensure the results do not deviate and that they are in fact reproducible.
When running OpenArena under all three tested operating systems, Mac OS X came out ahead again at all resolutions from 800 x 600 through 1920 x 1080. When comparing Ubuntu 10.10 and Ubuntu 11.04 Alpha 2, the newer "Natty Narwhal" development build was slower than the "Maverick Meerkat" at resolutions of 800 x 600, 1024 x 768, and 1280 x 1024, but at the higher resolutions is where Ubuntu 11.04 Alpha 2 managed to pull ahead of its predecessor. Nevertheless, at these higher resolutions, the Intel graphics under Linux would not be considered playable for the Intel GMA 950 IGP.
X-Plane 9 failed to run on either Ubuntu 10.10 or Ubuntu 11.04 Alpha 2, although we have been able to run it in the past on Mesa, but not at a playable frame-rate. Even with Mac OS X, X-Plane 9 could not hit 10 frames per second on the Mac Mini.