CPU-z will show you what speed your ram is running at. If your CPU is at 9.0 x 400 MHz and your memory is at 1:1 then it is also at 400 MHz or DDR2-800 speed. Your memory speed is tied to your FSB speed.

jgree32: Did you update to a recent bios? Which one if you did?

Going to 401 puts less strain on your northbridge. You might want to try 8.0 x 450 MHz and then use the P965StrapTweaker to see if you can regain the lost performance by getting back on the faster strap. This tweak seems to let you run on the fast strap at a much higher FSB speed without losing stability. I used to boot up at FSB 400 and then try to SetFSB higher but the most I could get to was about 450 on the fast strap. With the tweaker I can go over 500 FSB without any issues. Prime stable at 533 MHz FSB on the fast strap made me smile. Max out your NB voltage when testing so that doesn't hold you back. The Asus Commando with the 965 chipset lets you set the northbridge voltage to over 2.00 volts in the bios so 1.65 volts isn't going to hurt anything.
Thought you'd get a kick out of this. Couldn't get it stable for anything at 9x355 so decided to try 1.65V Northbridge......Result is one smoked northbridge. Smelled it shortly after boot then it froze at post. Took off northbridge heat sink and confirmed it is the source of the smell. Looks like another RMA i guess........