Adobe Premiere Pro CS4 and After Effects

Hello,

I have a Dell XPS 430-121b computer (Q8300 2.5, 6gb DD3 Ram). My Video card is an ATI HD 3650. Do I HAVE to use a Raid 0 setup on my two drives (currently, I have a 1TB drive and a 750TB drive, and I know that Raid 0 needs to match)? I will be editing AVCHD footage from a HMC-40 camcorder. Also, if I do have to use Raid 0 setup, can I add one more drive (1TB) and use Raid 0 on only two of the three drives? Keeping my original drive as it currently is? And YES, I am a newbie  ... Thanks for any help you may provide.

Greg