Yes, the cache size upping is a great little tweak, also turning on tripple buffering in my drivers also helped. If you use vSync, when the framerate dips below 60, it is halved to 30 and so on. Enabling tripple buffering stops this. You can change anisitropy also, I heard that it defaults to 8 in the config, so obviously lowering that will help. There are no two ways about it, though, the game is a beast.
Edit: mine is set to 512 and it works rather well.