Windows gaming and secondary SSD

I suppose I'm wondering how much games rely on Windows files, or are they all different? I have 2 SSDs, one high performance 240gb and one not so high performance 120gb. I currently have Windows on the slower 120gb. I also have a lot of games. Should I put Windows on the faster drive?
 
Solution
Yes, you should put the OS on the faster drive.
But you would not see a difference either way.

Another question is - Would your games fit on the 120GB drive?