PC4200 RAM will work in any mobo that supports DDR RAM. My AI7 and IC7 only "officially" support PC3200, but I've used PC3000, PC3200, PC3500, PC4000, and PC4200 RAM in them. That said, if you have a 533 bus 2.4, you don't need PC4200 at all. But, if you plan to migrate the RAM to a new system someday in the future, then it might be worth it. But, PC3200 will work just fine. Want a good mobo? Abit AI7.