Memory, as this card is severly memory bandwidth limited. only 128bit bus. But I would shoot for XT speeds which are 475/525. Mine is doing about 500/500 right now and I think I am limited by heat. Great little card. Its my filler till R520 Time.
dont remeber i found an article about the mem thats on the x700 awhile back its rated to like 600mhz or more i think ill try to find the article again. mines a reg ati off the shelf card too. just found the info took the heatsink off so i could find the numbers on it but heres the page