try the previously mentioned troubleshooting methods and see if it helps.

imho your specs should be able to play WoW on all medium or even high settings.
so it may be other issues such as addons, or sounds or your background applications.

When checking your addons,

1. Turn them off one at a time to find the culprit.
2. If that doesn't work, delete addon folder in WorldofWarcraft/Interface/Addons.
3. If that doesn't work, delete the *.lua file (e.g. for Decursive it's going to be Decursive.lua). It's in the WoW/WTF and WoW/WTF/CharacterName . Best is to use the Windows Search function to look for *.lua files to be deleted.

You can cut it short by deleting the WTF folders but you'll also lose your macro file (usually macros*.txt files, there's alot of them).

4. If that doesn't work, it's probably an incompatibility with another addon or one of the libraries isn't updated. If you're using Ace2-based addon (e.g Cartographer, Omen, BigWigs), use a software named WoWAceUpdater.exe to update these files with Externals option on.

5. If it's already too much of a hassle, delete the entire WTF and Interface/Addons folder and start from scratch. Some of the older addons do not delete the older files which in turn can interfer with the addon that you want on.

Note : The biggest headache whenever a new patch comes out is any addon that makes changes to the UI (User Interface). Example was when patch 2.1 (or was it patch 2.2) came out, it crippled all Bongos and XPerl users. Either the entire WoW interface look weird or there are bizarre buttons popping up here and there.

Note2 : Try to find out where the addon author updates regularly. Example : ItemRack is updated at WoWinterface.com and not regularly at WoW.Curse.com. Although Curse.com is huge, it doesn't mean that it gets the latest updates.

correction: turning ALL the addons off, THEN turning them on 1 by 1 to check for problematic addons is a better method

ok my prob solved by downclock the core speed.

but no moar tearing!

thanks quaza for pointing amd tools!

np, if its solved by downclocking the GPU core speed then its prolly overheating issues. can consider 3rd party cooling if you wanna get the core speed back up