In addition to burst transfers, the AGP bus has extra signal wires, which it uses to do "pipelining" and "sidebanding." Pipelining is where a video card on the AGP bus sends a request for data, but unlike with PCI, it can send more requests for data without having to wait for the data from the first request to arrive. Sidebanding is where, while the video card on the AGP bus is sending data in response to previous requests, more requests can be sent simultaneously via eight sideband address wires. So not only does an AGP video card not have to wait for data to come from a request before it can send the next request, it can send the next request while data is in the middle of being sent.

Pipelining and sidebanding increase AGP's efficiency over PCI, allowing AGP get much closer to its 528MB/s peak theoretical speed in normal use than PCI can get to its 132MB/s theoretical speed in normal use.

PCI supports DMA (Direct Memory Access) of textures in main memory, but there is no built-in support for directly using textures in main memory. Instead, most PCI video cards have to transfer textures to their local memory to use the textures. Some PCI video cards support proprietary methods of texturing directly from main memory, but the relatively slow speed of the PCI bus (when compared to the speed of the AGP bus) makes such methods extremely slow.

In addition to DMA, AGP supports DIME (DIrect Memory Execute) of textures in main memory. DIME is where an AGP video card can use textures in main memory as if they were in the card's onboard memory. If a game requires 32MB of textures and an AGP video card has only 16MB of memory available for texturing, the textures can be stored in main memory as opposed to in the video card's memory. The video card can then access the textures from main memory and use them as if they were in the card's own memory. Some AGP video cards do not support DIME but can still use DMA and/or their own methods for using textures directly from main memory.

The speed of AGP, even at 528MB/s, is still too slow for most games to use DIME well. When you consider that the 166MHz SDRAM and 64-bit memory bus of the Diamond Stealth 540 III Xtreme (that's about 1.3GB/s of bandwidth) limits it to the low-end of the graphics heap, you should soon realize that AGP texturing will cripple performance, even at the 1056MB/s speeds of AGP 4X. With PCI's 132MB/s transfer rate, DMA texture use with proprietary methods looks even worse. The usefulness of the AGP's bandwidth comes in getting information from the CPU to the graphics card as quickly as the graphics card can process it, not from DIME of textures.