Quote Originally Posted by 'JoKer76',index.php?page=Thread&postID=105185#post 105185
Running an instance on that monitor and a 2nd instance on another monitor seriously cripples my frame rates.
There is a known issue when trying to run multiple instances of WOW on multiple monitors but there is a fix.

The FPS difference between EXTENDED desktop and STRETCHED desktop is HUGE. Not sure what kind of video card you are using, but on my ATI Control Panel, go to "Displays Manager", then right click on the 2nd monitor. Select "Stretch desktop Horizontally" and apply. If you use maximizer or PiP you will need to change your settings, but it's worth it.

I go from 10 FPS to 60 FPS on my machine with that little change.

Good Luck!