Even more important than added bandwidth is the dedicated video interface that AGP provides. It would be interesting to see more benchmarks that try to run a video test while doing other things at the same time and see if there is more of a difference. This could mean opening the door to such things as faster HDD access and faster network cards. As for PCI sharing access, this is true, but you can always have multiple PCI buses. In fact this is a requirement if you want to have PCI-64 and regular PCI cards in the same machine.
Life is complex.
It has real and imaginary parts. In terms of data transfer, AGP will always be more efficient than PCI, because AGP is capable of transferring bursts, while PCI makes 1 data request and gets one packet back. The inherent latency on every transfer just makes it crappy compared to one latency cycle on an AGP burst. In terms of data transfer, AGP will always be more efficient than PCI, because AGP is capable of transferring bursts, while PCI makes 1 data request and gets one packet back. The inherent latency on every transfer just makes it crappy compared to one latency cycle on an AGP burst.