Schaduw kwam een link afgeven naar Tom's Hardware Guide, waar een artikel te vinden is waarin de impact van AGP snelheden is onderzocht. Zoals de meesten van ons wel kunnen verwachten blijkt dat we van AGP 4x geen grote performance winst hoeven te verwachten; de bandbreedte van het intern geheugen is daar momenteel gewoon niet toereikend voor:
If you should have read my good old article 'AGP - A New Interface for Graphic Accelerators' you may recall that back then I demanded the 100 MHz memory bus to supply enough bandwidth for the AGP and the other parts of a system that require memory access at the same time. Today the demands are of course even higher. The AGP's data bandwidth can only be used completely if the system has ample memory bandwidth. The memory is permanently accessed by several system devices at the same time, as the CPU, PCI-Masters, DMA-devices and the AGP. If the AGP is to supply its full bandwidth, the memory bandwidth needs to be at least as high as the AGP-bandwidth, since the memory is where the data to the AGP-device comes from under most circumstances. In case of AGP4x and its 1066 MB/s at least PC133-memory is required, which offers exactly the same bandwidth of 64-bit times 133 MHz = 1066 MB/s. We remember however that the AGP has never got the memory bandwidth to its own disposal; it has to share it with the rest, so that AGP4x can only live up to its full capacity when the system is either using RDRAM or the upcoming DDR-SDRAM. One PC800 RDRAM-channel, as used in platforms with Intel's 820-chipset, supplies 1.6 GB/s, PC200 DDR-SDRAM offers the same, PC266 DDR-SDRAM raises that to 2.1 GB/s and finally two PC800 RDRAM-channels, as found in platforms with Intel's 840-chipset, can supply even 3.2 GB/s. Platforms with one of those memory types will show better performance than PC100 or PC133-platforms as software is starting to make usage of AGP4x.