PCI Express Graphics Cards
All PCI Express graphics cards are connected via x16 PCI Express slot. The resulting bandwidth is 4 GB/s upstream as well as downstream, which easily surpasses the conventional AGP by a factor of four. It's still difficult to predict what this will mean in practice. However, we will be looking at this topic more closely in a separate article.
Confusion Through Compatibility?
The upward and downward compatibility with different PCI Express speeds could easily cause lots of confusion because the mechanical structure of a PCI Express connector reveals very little about the PCI Express speed at which it might run. For example, it will be possible to plug a x8 PCI Express card (in the later generations) into a faster x16 slot, while in reality the card only runs with four lines, i.e. x4 PCI Express.