pci-
e > agp > pci
PCI (32bit bus ,33MHz clock) = Peak transfer rate up to 133Mb/sec (32bit x 33MHz / 8bits/byte)
AGP-1x (32bit ,66MHz clock)= Peak transfer rate up to 266Mb/sec
AGP-2x (32bit ,66MHz clock-double pumped)=Peak transfer rate 533Mb/sec
AGP-4x (32bit ,66MHz clock-quad pumped)= Peak transfer rate 1066Mb/sec
AGP-8x (32bit ,66MHz clock-8 strobes per clock) =Peak transfer rate 2133Mb/sec
PCI-E x1 = 256Mb/sec upload/download (512Mb/sec combined)
PCI-E x4 = 1Gb/sec upload/download (2Gb/sec combined)
PCI-E x8 (v1.x) = 2GB/sec upload/download (4Gb/sec combined)
PCI-E x8 (v2.0)= 4Gb/sec upload/download (8Gb/sec combined)
PCI-E x16 (v1.x)= 4Gb/sec upload/download (8Gb/sec combined)
PCI-E x16 (v2.0)= 8GB/sec upload/download (16Gb/sec combined)