I have a Radeon 9800pro 128mb... upon using a program called cpu-z to check if my old CPU is northwood or willamete I discovered something about aperture size on AGP description box... It said: 64mb... Does this mean I'm not using 128mb ???
No just leave Aperture at 64MB. You shouldn't ever want to use system RAM over onboard graphic RAM anyway. For comparison, system RAM over AGP8X is about 2GB/s, while the 9800pro RAM is about 21GB/s.