You gotta balnce both, but when the chips are down for most things
cpu performance is king, just look at the Pentium M with it's single chanel DDR333, but there comes a point where memory througput is the limit for certain apps
If you take the differance between socket 754 and 939, 939 has double the memory bandiwdth, but
cpu's of equal ratings are only 200mhz apart
Your memory won't limit the clock speed the
cpu can reach