@Skrimshaw - I'm using Maximizer 1.4.1 that I found on Curse. I did purchase Keyclone and gave it a try. I didn't any noticeable frame rate improvement over Maximizer though. It did get me to playing with WoW's maxfps and maxfpsbk command lines though, which does affect my framerate. What resolutions do you run at on both your monitors?

@Bovidae - I wasn't using Keyclone, but I experimented with it and didn't better my results. To my knowledge a 32-bit application in Windows is limited to 2gb of memory. Windows should handle the memory dynamically though, since I'm running multiple 32-bit applications. When running all 5 clients, my system is only using about 2.5 GB. I think you are referring to the fact that most 32-bit operating systems have a 4GB limit of addressable memory.

@Nitro - It never hits 100%, stays around 65%-85%. Some of the cores are maxing out though.

@Aradar - You appear to be having my similar results. When you say add 2 clients windowed, do you mean on the same screen or one copy of WoW on each screen? Do you currently with your 5 copies on one screen with Maximizer or do you just alt-tab or whatever between the windows?

@Bollwerk - As stated before Aero vs Basic is not affecting my performance.

My slow frame rate appears to be related to the second screen. I tried a single screen solution where I put my main on the top of the screen at a resolution of 1280x560 stretched out to 2560x1120, then my 4 slaves across the bottom of the screen at 640x480 each. This works perfect. I get a smooth 60fps on my main. I'm still a little puzzled why I can't run the 4 slaves on the 2nd monitor without affecting the main's FPS though, especially since I'm running them off a separate card.

On a side note, I'm intrigued with Keyclones new PIP function. I'm not sure my thinking and playing style aligns with Keyclones though. Keyclone appears to be a software version of a keyboard multiplexer, where pressing key X would send X to each copy of WoW. I've been using HotkeyNet which allows me to capture X and then send X, Y, or/and Z to any or all copies of WoW running. Is this correct? Perhaps I could use Keyclone and HotkeyNet. For others reading this, another solution is AutoHotkey, but HotkeyNet seemed do be a little more straight forward to me .