I just installed an XFX Ti4200 128, overclocked it w/ Riva from 250/513 to 270/540, and got a 9821 with this system:
P4 2.0 on Intel D850GB Motherboard (4X AGP) (FSB 100 MHz)
512 Rambus RAM
For $85, I quadrupled (almost) my benchmark over the GF2 MX400 64 I had. I figure this will have to do until I get a new (faster) computer w/ an 8x AGP motherboard.
Anybody think more Rambus would help?