Playing Crysis in BootCamp with the Radeon 5870 i noticed some occasional graphic errors, with spiky artifacts appearing on the screen. I didn't think too much of that until i got the same thing in Metro 2033. There they were much more frequent and were only appearing after a couple minutes of play. Using the Ati Catalyst Center i checked the temperature and fan speed. Temperature was 71 °C and fan speed was at 21%. When setting the fan speed manually to a higher number, the gpu stays cool and i can play without errors. So it appears, there is an issue with the automatic fan control, where it doesn't rev up high enough. I don't wan't to set a manual value though, as it is too much most of the time and get's really loud. I use the card in a 2008 Mac Pro. Has anyone else encountered or solved this problem?