AGP is made by Intel. AGP use in a graphic card, which help to access memory directly with high bandwidth. Its help to increase graphic performance. AGP now comes with high quality interface PCI Card. Due to it great performance many hardware company now gives inbuilt AGP in all motherboards and Graphic cards. The standard bandwidth AGP card now days most famous in the world. Most video cards run at 8x.

Here is some refer:

1X - 266MBps
2X - 533MBps
4X - 1.07GBps
8X - 2.1GBps