Quake 2 tests 16 bit color OpenGL performance. The Xtreme soundly trounces the Cougar in all Quake 2 benchmarks we ran. In the less intensive demo1.dm2 tests, the lead is huge, and in the more intensive crusher.dm2 tests, the margin is significant though not quite as large. But the GA660, with its 128-bit memory path, pulls well ahead of the Xtreme in demo1.dm2 and at 1024x768 where the Xtreme's lower fill rate becomes a limiting factor. Whenever things get really intensive, such as when Quake 2 is running at high resolutions, the Xtreme's 64-bit memory bus limits the amount of data the graphics chip can get to and from graphics memory. The graphics chip idles while it waits for data from memory to make its way through the 64-bit memory bus. Still, the Xtreme makes a showing at high resolutions that other 64-bit cards should be jealous of. At lower resolutions, the narrowness of the memory bus does not slow things down nearly as much. Proof of this can be seen in how the Xtreme, surprisingly, actually beats the GA660 in lower resolutions in crusher.dm2. It seems that S3 has very talented engineers who managed to heavily optimize their card for low resolution OpenGL performance.