Without a doubt, the future belongs to the new PCI Express interface. However, the technology is still too new to judge when exactly this future will be upon us; in other words, when PCI Express will become a "must-have". So far, only motherboards using Intel chipsets offer PCI Express at all, although the competition supporting AMD is set to go.
A typical AGP 8x slot (top) and the new x16 PEG (PCI Express for Graphics) slot.
The different connectors. AGP on top, PCI Express below.
Where 3D performance is concerned, PCI Express offers at best minimal advantages over AGP models. Buyers looking to upgrade their graphics card won't be making a mistake if they pick up an AGP model, assuming that their system is reasonably powerful and up-to-date. However, if the potential upgrade would also include a new motherboard and a CPU, it's worth taking a look at PCI Express. Keep an eye on the price tag, though, as PCI Express systems on the whole aren't significantly faster than their AGP counterparts at the moment. In the end, it's up to the individual to decide how much an investment into the future is worth to them.
