I've had a tip that works for me as well as a bunch of other people.
The longer you play, the more the game seems to crawl along.
A quick runtime fix for this is to...
Change the screen resolution in the SK menu to anything... then change it back to what you want.
Just thought this would be a good tip for people to use.
Wow really, if only that what your idea. which it wasn't. Howdy Skept its Arbitergomez. your such a lier, but the truth needs to be told.