First off, system specs: Q6600 @ 3.2ghz, 8gb of OCZ ddr2 @800mhz memory, Nvidia GTX 260.

For the past 3 months i've been having a wierd FPS issue running 1680x1050 windowed mode on a monitor running at 1680x1050. Running 1 client at this resolution would cause me to get about 10-15 fps anywhere in wow. If I ran the game at any lower resolution the game would run just fine and get very high fps. Also if I switched to full screen and ran the game at 1680x1050 the game would run perfectly fine. After being frustrated for far too long I set my maximzer settings to simply run my main client @ 1440x900 and just have areas of my desktop visible.

About two weeks ago I noticed that whenever i would get an IM via digsby my fps would drop down to the dreaded 10-15 fps. Normally I would just expect this to be caused by wow losing focus but at this time my main client had its backround fps set to a high number. I then started to think something else was going on and I could be on to something. I relogged my wow client and enabled the windows border so I could drag my wow window around. I dragged my 1440x900 wow client to the bottom of the screen and as soon as any of the rendering surface crossed part of the task bar my fps dropped to 10-15 again. This even happened if part of the wow window touched the big vista start button which goes higher than the bar. Happy with my discover I set my maximizer setting to fill the screen except for a small sliver at the button to prevent the wow window crossing the Windows Vista Start menu button.

I was happy at first because I could now play wow the way I wanted to be playing with it. But after a while my bliss faded away because anytime I got an IM in the middle of a key fight my fps would plummet and sometimes would cause me to die. At this time I was using the Windows Vista Basic profile for my desktop appearance. I figured this was forcing some sort of wierd sofware rendering bug to happen and decided to try switching to Windows Classic or Windows Standard and maybe this would fix the issue. Neither of these options resolved the issue.

At this point I started thinking about a rendering issue I was having on my software project (I'm a C# developer working with Windows Presentation Foundation or WPF). Our software uses WPF which also uses some of the Aero features to render certain video effects in our application. Because of this I also knew that Aero actually takes advantage of DirectX rendering and can be hardware accelerated. I was confident that the issue I was having was caused by windows forcing software rendering to happen over hardware accelerated rendering. I then correctly surmised if this was the case and I turned Aero back on that the issue would go away. After turning Aero back on and doing a little Jig this particular fps issue is now gone for good. Of course this doesn't help me in dalaran or Wintersgrasp but you have to start somewhere.

This is the thread where I initially talked about my fps issue over 3 months ago:
Weird FPS issue in windows mode.

Go figure, Aero saves the day! :thumbup: