It might be a Crossfire issues for you, that's all I can think of.
i think someone told me that was the cause of a problem i was having with Shift 2, that it did not support crossfire or something. although i only have 1 physical card, i guess having 2 GPU's on the card is kind of like a crossfire and that's how the computer sees it? if that's the case, any game that does not support crossfire well, i will not get good performance from.
is it possible to disable 1 GPU and just run 1? to see if it is an issue with that?
Did you recently get the game and its not running well or this is a new issue?
i just got the game, this is my first experience with it and i immediately noticed the random frame rate issues. using FRAPS, i see it drop to the 20's at times but it'll run well over 40 at other times.
ither way off the top of my head I suggest you try running UE3Redist under Steam\steamapps\common\Red Orchestra 2\Binaries\Windows and also lower make sure your sound setting for amount of voices or something (I forgot the name of the exact setting) is set to no higher than 64.
i ran the UE3Redist again, lowered the maximum amount of voices from 64 to 32, and also changed the sound quality setting from high to low - does not help.