A ram disk only helped my games with the loading times. This game loads most of the round before you do the race your running, so I don't think it would help. The fps would be depending on your gpu and cpu. The only way to get more fps would to get a better gpu or cpu that I know of. I tried the ram disk with this game and 2012 and didn't help the game play at all.
I Do not know with the Games m8,,,,,,,
I Only run @720p 60fps and thats fine for me,,,,,,,
I Run Photoshop CS6 3D ,,,,,From a RamDisk 8GB Scratch Disk and the Results are Awesome really fast but my CPU Are 19Ghz so its pretty fast anyway,,,,,,,,,
I Have a 3GB GTX 580 Classified its a 1000W Card Runs all my games on max Resolution @1080p with Ultra Settings I think this is probably the Highest it will be happy with ,,,
But I use 720p Because the Difference between 720p/1080p for rendering Videos is about double,,,,,,,,,,,,,,
But for Example with the Software that I run I can Render and upload a Video at 720p in Between Sprint Races Online,,,,,,,,,,,,,,