Multiple cores are old hat, particularly in the GPU world where you can have hundreds of simultaneous processing units working in concert, but multiple GPUs on the same PCB, that's still exciting territory (not least because of the crazy thermal and power requirements that go with it). AMD and NVIDIA are set to clash horns on this field of battle once again, fishing for mindshare as much as they are for high premium sales, with the Radeon HD 6990 and GeForce GTX 590, respectively. The former has already slippe
