[tomthedrummer1992]

I have some PC-6400 800MHZ RAM running in dual channel mode.

However, when I open up CPU-Z, for each stick of RAM it says the max bandwidth is 400MHZ.

Surely this should be 800MHZ? I'm sure it was 800 in the past!

Any ideas how to change it?

Never done ANY overclocking before!!!

[thingie2]

that might be because it's DDR2, so in effect it's doubling the frequency (from 400MHz to 800MHz)

[tomthedrummer1992]

I was under the impression that each stick should have 800MHZ bandwidth. I'm wondering if there is a function on the mobo with turns it down when it's not all needed. Like the speedstep on Core 2 Duo processors.

[thingie2]

They do both have 800MHz, because it's DDR2 which means it has 2 clocks for every real clock. basicly, it clocks at each change of state (high or low), whilst DDR1 only clocks at every other state (every time it goes high, or every time it goes low) so even though it has an actual clock of 400MHz, it will be clocking twice for every actual clock, giving you 800MHz. For more info, and possible a better explanation try reading this page.

[Carbon]

it doesn't matter anyway. Nobody but those with (overclocked) Wolfdales is going to hit over 400mhz on the FSB.