Older boards automatically slow down the ram to match the procs fsb (if I'm not mistaken, correct me if I'm wrong experts!!!). I have kingston DDR400 value ram(taken from my main AMD X2 rig) running in an older P4 rig. It has been automatically downclocked to DDR266 as well. But that just means you can probably oc like crazy with the ram since your ram is rated at 400mhz, although you'll have to loosen your timings in my case (once again correct me if I'm wrong).