PCI Express
The PCI Express x16 is intended to ultimately replace the AGP bus along with the PCI-X and the Conventional PCI.
PCI express x16 is a faster slot
There is no latest AGP bus. The most recent bus designed for high performance equipment is PCI-E. And x16 has the highest bandwidth.
PCI Express x16 at 2.5-40 GHz whereas AGP tops out at over 100 MHz
PCI express is faster
PCI express x16 is much faster than AGP.
No AGP is older and slower. AGP was superseded PCI Express in 2004.
PCI , AGP and PCI Express
PCI express is about twice as fast as AGP and will ultimately replace AGP.
It's safe to say that agp has already been replaced by pci express.
pci express (PCIe)