Deluxe Quick Access Treat Bag Two Hard Drives Without Raid?

Two hard drives without raid? - deluxe quick access treat bag

I have two hard drives, Western Digital Caviar 250 GB with 8 MB cache and a 320 GB Western Digital Caviar with 16 MB cache.

I wonder if the operating system rely on one and games on the other side to improve the performance of a?

Can access to a computer both at once? Its an AMD 64X2 4400 + with an A8N32-SLI Deluxe. I have 4 GB RAM Corsair XMS 3200th

I know RAID 0 is faster, but I've got 2 hard drives do not agree with me, for now, so the attempt to make a timely way.