As long as the memory supports the voltage and physical requirements (3.3 volts, unbuffered, 168 pin) of the motherboard (and vice-versa) the PC-133 SDRAM will work just fine. Lots of people use faster ram than required for thier system to help in overclocking the system bus. OC'ing the sys bus puts a strain on the other components in the bus path and the higher their spec, the better able they will be in handling the increased load brought on by the OC'ing of the bus. That board has a BX chipset which supports a 100mhz front side bus, so putting PC-133 SDRAM (133mhz) in it is fine because it won't "bog-down" your sys bus (like if you put PC-66 SDRAM in it) but in fact, it theoretically leaves 33mhz of memory bandwidth headroom for you to play with!