Nvidia all agree that the faster bus will give better bandwidth and scalability, allow large request size and pipeline depths, and give isochronous support. The bandwidth will deliver simultaneous 8GB/s concurrent peak bandwidth in X16 mode. PCI Express will also provide a pipeline depth of up to 256.
Graphics cards using PCI Express tech will, however, require 75 watts max, and that means a few things. First, the 12 volts on an ATX power supply won't do the trick. The answer will be to use a 2x12 connector with the same pinouts as server SSIs, which requires a 300W power supply. The other problem is that machines will need to use side panel vents, ducting, and use large fans. |
Not only CPUs will need more extreme cooling solutions in the future, it seems that graphics cards will need them to..
Some more information about differences between managing non-local memory in AGP and PCI Express can be found at The Inquirer