Yes, I've had 4x2GB of Corsair DDR2 800 RAM on my P5Q Pro since mid-July with absolutely no problems, including multiple iterations of stress testing. My only OC'ing has been about 10% controlled by the Asus software, agin no problem. The Corsair I purchased (6400C5DHX) has the extra large attached heat sinks but they don't interfere with anything, including the Arctic Freezer 7 Pro CPU cooler that I added in place of the standard Intel cooler. Great MoBo. Great RAM.