FPS is very slow on just 1 of 4 windows of D3.

I'm running 4 windows of D3 with 4 Witch Doctors or 4 Monks. I have it running as a quadrant on my 30 inch display.
Quadrant 1 is running less than half the FPS of Quadrant 2, 3, 4.

-One of the things I tried was switch the accounts to another quadrant to see if the lower FPS would follow. It stayed in Quadrant 1.

-At first I was running all windows at 30 FPS setting in ISBOXER to relieve some processing stress. Then I decided to change it to 60 FPS since I felt my graphics card and CPU can handle it. I have a Nvidia 690GTX, Intel 3930K 6 core CPU, 32GB Corsair Dominator RAM, 256GB SSD.

-After I was running the windows in 60 FPS is when I noticed that D3 in Quadrant 1 was running slower. I changed all FPS back to 30 using the ISBOXER setup. Never touched the FPS setting in the D3 options menu. Quadrant 1 is still running at half the FPS as the rest.

-I used the Wizard to setup for default configuration of D3. Only thing I've changed was the FPS and the CPU core processing (6 core CPU: 12 with hyperthreading, so I divided each window to 3 cores.

-Anyone have advise with this issue? Any ideas or suggestions would be great!

-Oh yea I don't know if this will help but, when I changed the ingame resolution of 1280x800 to 2560x1600, the FPS all ran at 30!, so I bumped up to 60 FPS and for a few minutes all windows were running at 60 FPS all smooth and great! But after a few minutes quadrant 1 slowed back to 18-20 FPS, while the rest are at full 60 FPS.

I don't know whats going on... Please help.

[lax]

We solved this in IRC but I'll briefly recap.

I explained that this concerned me:

-I used the Wizard to setup for default configuration of D3. Only thing I've changed was the FPS and the CPU core processing (6 core CPU: 12 with hyperthreading, so I divided each window to 3 cores.

Putting each window on 3 cores was likely to be a major problem due to half of the cores being logical cores. So half of the game instances were using 1 real and 2 fake CPU cores, while the other half were using 1 fake and 2 real CPU cores.

I suggested he use the "Select all CPUs with every window" strategy for smoother performance, and noted that ISBoxer 41's CPU Strategy Wizard will default to this setting for him, instead of the Round-robin strategy that ISBoxer 40 always defaults to.

This seems to have worked.