Originally posted by: glugglug
Set it as small as possible, even if this means setting it to 0. You
DON'T BENEFIT FROM IT AT ALL unless you are using a video card with less than 16MB. The only affect your AGP aperture really has in practice is it takes up part of the 976MB of virtual address space which Windows uses for kernel space & disk cache.
Keeping textures on the video card is always much faster than keeping them in system RAM and sending them through the AGP bus. There are
ZERO games which use more memory for textures than fits on the minimum required card because it would make the games unplayably slow.
Edit:
Link