What is the fastest replacement for my AMD 1200 (socket a, 462 pins, K7 200 bus)? My mobo is a ASUS (sock-a, atx, a7v133a, via133a). Will a AMD Sempron 2500+ (Thoroughbred 333MHz FSB 256KB L2 Cache Socket A) work? I don't want to upgrade my mobo as I've already invested in memory.