[quote1206973759=MrQ]
Currently there is a new updated PCI-E 16x its referred to as 2.0. It is much faster and I think it utilizes more bandwdth than before. The new 9xxx series Nvidia cards are the only(I have no idea about ATI, nor do I care too

) as far as I know, cards to take advantage this technology. It comes on the latest nvidia 7xx chipset boards.
[/quote1206973759]
Actually, the ATI hd2600 and 2400 were the first released pcie 2.0 cards, and I'm pretty sure the rd780 was the first chipset that supported it... PCI-E adds more bandwidth and allows up to 300w through-port, but every card is still backwards and forwards compatible, in the same nature AGP was (4x could run in a 2x slot, and a 2x could run in a 4x slot). It's not really taking 'advantage' of anything... just making sure the bus specification is updated before it bottlenecks the bleed-edge performance range.
As modern GFX chips are pcie-native, it's obvious that they perform better than their AGP-brothers (which use a host chip to run PCIE on AGP, which takes off about 3%), not to mention that modern chipsets with modern cpu's would definitely outperform an old AGP-based system. But if your talking about the actual speed of the bus, there's not a single chip out there yet that uses more than AGP 8x could provide, but with AGP you have no choice of multi-gpu's.
So basically it all comes down to the basic fact if you want to run a modern gaming pc, with support for the newest processors and fastest memory, you have no choice but to go with a pci-e chipset.