Unless you are using the ray-traced renderer to create 3d geometry (which is now considered obsolete), the GPU does pretty much nothing in CS6. It certainly doesn't affect render times. Now, if you ARE using the ray-traced renderer to create 3d geometry in CS6, you need to use older cards to accelerate the geometry you're creating. NVIDIA changed the Optix library the ray-traced renderer depends on and CS6 doesn't work with cards in the 900 series or later (even if you manually add your card via the "hack" that most people suggest).
Now, if you're not using the ray-traced renderer, the GPU is likely not the issue, but we can't really begin to help diagnosing what is causing your problem. Read this post for the kind of thing that would be helpful
My render times are fine, its just RAM previewing. It plays in 21-24 fps in a 60fps compostion. I removed the card and tried to see if having no video card would work and it did. Only problem is now I can't play games unless I turn my pc off and put it in and install my drivers.
Go into your user preferences, there is most likely an option in the hardware dialogue to turn off GPU compute, or something like that. However, I do admit this is quite strange, I don't see why having no GPU would faster than having one, or more. I have had no problems with my GTX 480 which I had up until January and the GTX 1070 I've upgraded to.
It's weird that no GPU works better than having a GPU. What operating system are you using?
UPDATE: New processor, RAM upgrade, and motherboard upgrade. Problem still occurring. Ram previewing is faster (due to new and more ram) BUT, playing back the ram preview is still not in realtime.
EVGA GTX 970
16GB HYPERX FURYX 1600MHz DDR3
MSI H81-I MOTHERBOARD
WINDOWS 7 PRO
What, exact, version of AE are you using?