1.5gb ram only showing 1g at 400mhz fsb

[AceIlluminati]

I upgraded my processor from an Athlon xp 2400+(266mhz) to an Athlon XP 3200+(400mhz) and when I set the bios to 400 windows only shows 1 gig of ram instead of 1.5, if i turn fsb down to 333mhz the ram shows 1.5gb. The ram is 3 512's one is geil ddr400 cl2.5-8-4-4 and the other 2 512's are aeneon pc3200 cl3.0.

I ran cpu-z and it shows 1.5 gb of ram. I dont know if its just windows xp not showing the other 512 kb or what.

 

[Eviltwin17]

sometimes when you add more ram with windows xp it doesnt register unless you underclock it. For instance my corsair value select always underclocks itself to 333 from 400 when i add more than a gig. Dunno why. It just does.