The guys at THG tape off the pins on a couple of video cards that force the cards to run at x1, x4, & x8 PCIe speeds, & benchmark the cards to see what difference bandwidth plays in their performance. Some very interesting differences in the numbers between the ATi & nVidia cards; shows how different their chip architectures are.

"Today, almost every new computer utilizes PCI Express to hook up integrated or discrete graphics engines. Graphics solutions have advanced tremendously and we believe it's time for a new analysis, to find out the answer to this question: How much bandwidth does graphics really need?"