Firstly, I'm unsure why you're posting your Q in the AE forum when your workflow is more defined within PPro.
Anyways, you need to know more about the Mercury Engine, an Adobe creation/development. The Mercury Engine allows Adobe applications to harness the processing speed of GPU for smoother/faster playback of PPro as well as to allow for faster AND better processing of a number of effects, in PPro.
Prior to CS6, the Mercury Engine was used by PPro to achieve the stuff I mentioned earlier. With CS6, other Adobe applications have started to leverage on the Mercury Engine.
AE CS6 has not leveraged on the Mercury Engine. Instead it's hardware accelerated offering for CS6 involves its new Ray-traycing Engine which works within nVidia's Optix ray-tracing technology.
More info on AE CS6 (which relates to PPro even if its not stated explicitly) here
http://tv.adobe.com/watch/cs6-creative-cloud-feature-tour-for-video/how-to-...
More on Optix here ->
http://www.nvidia.com/object/optix.html
Info on nVidia cards that work best with PPro (decent-to-good info but not great cos they left out the Quadro cards) ->
http://www.studio1productions.com/Articles/PremiereCS5.htm
In a nutshell, you will need a faster hard-drive than your existing 5400RPM make. You'll want a GPU that allows Adobe's CS6 products to leverage on its Mercury Engine. Your RAM stipulation also needs a boost. Ideally, you will want each of your CPU cores to have access to 2GB of RAM. You can of course limit the number of CPU cores and RAM that are accessible to CS6 apps.
HTH
RoRK
Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer
