Should I install OS and games on the same raptor?

I decided to buy a 150gb raptor and a 320 gb 7200.10 seagate hard drives.

Orginally I was going to install only my OS on the 150gb raptor. Now im wondering if i should also install my games on the raptor as well as the OS and put all of my applications on the 7200.10 hard drive. Would this be the way to go?

Or will it be faster to just have the OS on the 150gb raptor and put my games on the 7100.10 hard drive so they are not on the same hard drive?

Thanks!