Sorry, I’m afraid to say that my initial PCIe reviews are pretty horrific in terms of comparing the actual differences between PCI and AGP in a gaming situation due to the platform differences – it would be nice if we were able to get 3.4 or 3.6GHz Prescotts for both Socket 478 and LGA 775, but we don’t command similar sway with Intel as some, such as Anand or Toms do (although if anyone reading could assist that situation that would be rather nice). However, even if that were the situation we’re still not able to get 100% like for like platforms so there will always be some difference – we’ll have to see if the AGP and PCIe capable northbridge from VIA is released with both AGP and PEG x16 slots on a motherboard to be able to get try like for like equivalence (and even then we are working on the assumption that these will both be good implementations).
In general terms the AGP X800 XT PE clocked to XT speeds (500/500) is more or less a little behind the PCIe XT in all cases, but this is largely due to the CPU differences – even when things begin to get fill-rate constrained the PCIe board appears to be faster still (but remember, the AGP board is a PE running at XT speeds, so its memory timing may not be set up for an XT configuration). We can certainly see that when bus bandwidth is an issue the PCIe boards have a significant advantage.
