Which expansion bus architecture is used exclusively for display support?

Answer 1

This is a kind of trick question because there are actually two graphics-only technologies. One could argue the second is only a version of a larger architecture. But, it is "A separate connector used exclusively for graphics", so I leave the semantics up to you.

The short answer(s):

AGP (for the purists)

AGP and PCIe 16x (for the practical)

The long answer:

The original graphics-only architecture is Accelerated Graphics Port or AGP. AGP was created to enable video data transfer rates higher than PCI video cards.

AGP technology advanced over time, resulting in four different modes:

AGP 1x was the 1st, transferring data at 266MBs per second.

AGP 2x transfers data at 533MBs per second.

AGP 4x transfers data at 1.07GBs per second.

AGP 8x, the final AGP, transferred data at a whopping 2.14GBs per second. Quite an improvement over PCI.

The other graphics-only port is now in the process of replacing AGP. AND it's "back to PCI" (sort of).

PCI Express x16 transfers data at 4GBs per second, effectively doubling AGP 8x.

The possible controversy: PCI Express slots come in PCIe x1, x2, x4, x8, x16. All except PCIe x16 slots are used for many things. PCIe x16 is used exclusively for video cards and has its own connector.