Accelerated Graphics Port

Accelerated Graphics Port (AGP) is a bus specification by Intel which provides low-cost 3D graphics cards faster access to main memory on personal computers than the original PCI bus specification.

Description
AGP dynamically allocates the PC's normal RAM to store the screen image and to support, and. AGP provides a coherent memory management design which allows scattered data in system memory to be read in rapid bursts. AGP reduces the overall cost of creating high-end graphics subsystems by using existing system memory.

Intel has built AGP into a chipset for its microprocessor. AGP cards are slightly longer than standard PCI cards. AGP operates at 66 MHz, doubled to 133 MHz, compared with standard PCI's 33 or 66 MHz. AGP allows for efficient use of memory, thereby helping 2D graphics performance as well.

Adoption by Apple
Apple Computer's first product with AGP on the motherboard was the Power Mac G4, through it was not included on the lowest-end model, code named "Yikes!", which was still based on the PCI-only architecture of the blue & white Power Mac G3. The Power Mac G5 introduced the faster PCI-X and eventually replaced AGP with PCI Express (PCIe).