We previously reported on various OpenGL-related graphics issues, including lags, stalls or slowdowns in video playback, artifacts or corruption (particularly when moving windows or scrolling) and more after updating to Mac OS X 10.6.4. This issue can affect various graphics-intensive applications, including a number of games (Steam, StarCraft 2, etc.), Photoshop, web browsers (Firefox, Safari) and more.
Our previous report on the issue includes a number of potential fixes, including re-applying the Mac OS X 10.6.4 combo update and, as a last resort, downgrading to Mac OS X 10.6.3. Several readers have since reported success with re-applying the combo update.
Speculation now holds that some cases of this issue may be caused by graphics card heat problems, which can cause degraded performance or the aforementioned artifact/garbling issues. As such, two new potential solutions have emerged.
Rest SMC. Some users have reported that resetting the SMC, which may restore proper fan behavior, thereby cooling graphics components, resolves this issue.
smcFanControl. Other users have resorted to the utility smcFanControl, which can control fan speed. Users report success in setting the fan speed to roughly 5,000 RPM when engaging in graphics-intense activities.