I bumped my gaming PC up to 24 gigs of ram for Christmas This allows me to use a ram disk for games.
Installing MW completely into ram make a massive difference in play-ability especially modded up MW.
It makes a even bigger difference with Skyrim, load times are near instant on most stuff.
There is lots of ram disk software out there that make it easy to move stuff in & out of the ram disk & you obviously need to have everything backed up because the ramdisk is gone when you shut down or reboot.
The Asus ram disk is the best I have tried hands down ... even with Steam it was a couple of clicks & you don't even have to change your desktop shortcuts!
It took less than 2 mins to move 12 gigs to the ram disk.
It would be hard to go back to the old way of playing after playing with a ram disk!