No, dual channel doesn't mess with the memory frequency at all. It increases the memory transfer rate by increasing the amount of information that can be transferred at a time. (If memory serves, by allowing a transfer of 128bps instead of 64bps.)
If you're running DDR2-800 in dual channel, the speed is 400MHz. (800MHz effective due to the
Double
Data
Rate.) It doesn't transfer at 800MHz, or 1600MHz.
the system FSB will be 1333, If I overclock the system fsb to 1600 my memory should match that in dual channel, right?
EFFECTIVE FSB is 1333, the actual rate is 333.33MHz. DDR ram runs at
Double
Data
Rate of this speed, or 667MHz. (this is assuming a 1:1 ratio with your FSB) If you overclocked your (effective) FSB to 1600, your base frequency will be 400MHz, and your RAM will be running at DDR2-800MHz.
I'm not sure you guys understand how this works, so I'll try to clue you in. Everything in your computer runs off of what I call a base frequency. This is the "default" speed that everything is ran off of. For instance, the FSB is quadpumped from this speed. If the base frequency is 250MHZ, then the FSB is 1000MHz. (250MHz * 4) If the CPU has a multiplier of 10, then the CPU speed is 2.5GHz. (250MHz * 10) If the ram is running on a 1:1 multiplier, then its running at DDR-500MHz. (250MHz * 2) By changing this base frequency you can make things run faster or slower.