I had an Athlon XP 2400+(166MHz FSB) and 2*512MB DDR1 400 RAM, I played around with the RAM timings and clock speed(333MHz or 400) and then ran some 3DMark to test the performance gain. Well, all I got was 1-5 3DMarks more or less and actually more with 333MHz and settings by SPD(guess those 1-5 3DMarks are pretty random actually) so I stopped playing around with that.