Online Gaming video stuttering in combat.

Longtime player of World of Warcraft for about the last 2 mos Ive developed an issue of stuttering in combat with multiple mobs, multiple players or alot of ground effects pretty much making the game unplayable. Prior to this the game ran perfectly this is a Alienware area 51 desktop I purchased in Dec 2011, still under warranty. Can't get ahold of tech support today for some odd reason even though its a weekday. System stats are i7 cpu 930 @ 2.8ghz, windows 7 64 bit, 6GB memory and ati radeon 5900 series video cards. I'll list things Ive tried on my own to resolve the issue and new issues that have developed since. First I corresponded with Blizzard tried deleting all gaming addons , turning down all graphics and windowed modes. Then I tried updating all drivers including most recent video drivers from ati's website. None of these things worked. At this point I reinstalled the game, this did not work. So I then reinstalled the Os fresh and reinstalled the game after updating all drivers defragmenting ect. Still having the same issue. In the meantime in the last few days one of my fans above my video cards has become very loud intermittantly checked my case and its clean as a whistle inside. Ive run system mechanic to optimize my pc and minimize programs at start up including shutdown my anti virus program with no effect as well. Recently I have run a PSA test and it passes all tests with the exception of my optical drive error code 2000-0147 this is another issue but don't think related to my gaming issue.I am not especially tech savvy so any help is appreciated sorry for the long post. Another thing to mention is during these episodes of stuttering I'm running a consistant 50-60 fps and I am also experiencing some sound issues occasionally with the video stutter.