Frame-Pacing Video Driver Aims to Fix Radeon HD 7990 Microstutter
When the Radeon HD 7990 first hit the market back in April, it didn’t get the sort of reception one might expect for a graphics card that could easily claim to be the world’s fastest. The trouble it encountered had been brewing for quite a while, as PC gamers became increasingly aware of a problem known as microstutter that plagues multi-GPU configurations like AMD’s CrossFire and Nvidia’s SLI.
The problem has to do with the fact that frames are rendered in interleaved fashion between the two GPUs. That division of labor ought to work well, at least in theory, but the GPUs can go out of sync, dispatching and delivering frames at uneven intervals. In the worst cases, the two GPUs might dispatch or deliver frames at practically the same time. The second frame doesn’t really offer any visual benefit when that happens, although its presence will inflate FPS averages.
Since the 7990 is a CrossFire-on-a-stick product with two GPUs lurking under its expansive cooler, it’s prone to micostuttering problems just like a pair of video cards would be… Tech-Report