Some interesting developements. It turns out that I already had:
Options "NvAGP" "1"
in my XF86Config file, but when I tried to change it to a 2 or 3, then the screen outputs strange characters, mostly in black and white but also in a strange neon green color, similar to the PASS color on bootup. So I tried:
lsmod | grep nvidia
nvidia 2068232 24
lsmod | grep agpgart
agpgart 31016 1 via-agp
cat /proc/drivers/nvidia/agp/status
Status: Disabled
Still disabled From my previous post, "NvAGP" "1" means that I am using the nvidia AGP driver, and 2 means that I am using the linux kernel AGP driver. I don't know what else to try. Is there some file somewhere where I could enable the AGP? I already checked the BIOS and everything is as it should be there.