PCI VS AGP Given the same video card, how fast is AGP compared to PCI? I'm not just talking about larger memory bandwidth but real life performance. The reason I asked is my bro bought a pci video card to play games. He now wants to upgrade his mobo/cpu that supports AGP. If I return the PCI vid card, it's minus 15% restocking fee but the new AGP card will cost the same in the end after the fee. So again, how big of a difference is AGP compared to PCI with the same video card? Should I return the PCI card for AGP?

Not knowing what cards you are looking at makes it impossible to render a decision on this. Assuming the cards are equal in memory the AGP will perform better. AGP ports are specifically designed to be used for graphics whereas PCI are designed to be used for just about anything. The AGP bus is much faster (PCI is 33mhz, agp is 66 x multiplier '1x, 2x, 4x, 8x,'). AGP is much better at texturing also. You will notice a difference using AGP as opposed to PCI assuming the cards are of similar memory. A 64mb PCI card would probably outdo a 16mb agp card, you get the idea. Why are there then still high end PCI cards out there you may ask? Right now I've not seen a dual agp slot motherboard. Many high end graphics programs are much easier to work with using two monitors. One screen is used for toolbars and such. The other to view what's going on with the object being worked on. You don't want to put a low end PCI graphics card in a computer that has the need for high end graphics processing.

"Given the same video card, how fast is AGP compared to PCI?" Between little and no difference, and its because any card that is made in both a pci and an agp version will not have a very powerful gpu on it, simply because a pci slot does not have enough wattage to drive a high powered gpu. So for instance if you are looking at a radeon 7000 pci vs radeon 7000 agp, neither is fast enough to cause the slower pci bus to be the bottleneck in performance - the gpu will be the bottleneck instead. Generally speaking, pci cards are insufficient for a 2003 gaming machine. What cards are you looking at here? If the new agp card costs about the same as the pci card you have, it may not be enough for gaming. The exceptions to what I just wrote are the mx440 and the radeon 9100. They both come in agp as well as pci versions, but are good mid-tier gaming cards. In each case the agp version will outperform the pci version by 10%-25% because they are powerful enough to cause the pci bus to become a bottleneck.