Is this a new problem?
Until now, have you mostly been working with smaller files?
Is PS the only computation and memory intensive program running slow? What about games? Do you do any video editing? Is so, how's that program running?
The first test I usually recommend is to simply open Task Manager (or equivalent if on a Mac) and see what program / process is chewing up your clock cycles.
In case the user might have missed something when looking at the Task Manager, my next recommendation is usually to turn off your internet connection, turn off all virus detection programs, indexing and other auto-start programs that you don't really need to run CS6 and test PS again.
Another thing to try is to post one of your larger files, time a few operations on it, and post the times and details. One of us will open it and run it on our machine and tell you how long these operations take on our machine.
Tom
PS - FWIW, I have a machine similar high end machine (except 64 G of RAM, several SSDs (1 for the OS and apps, 1 for various temp files, 1 for fast (user) working storage, etc.)), and it wouldn't even blink at most operations on a 500 MB file.