raid 0 or 5?
 

My moboard crapped out on me a week ago (socket 939 running an Opteron 175) so when I went to replace it I opted to abandon most of my older tech and go to the intel quadcore and P35 chipset. Picked up an Asus P5K Deluxe board and a Q6600 and have seen a huge increase in speed, particularly with rendering in AE and Vegas 8.
One of the older pieces of tech that I kept was an SI Ide raid controller that I've been using with a couple of 240 gb drives striped in raid 0 for my OS and applications. Since my new moboard supports SATA raid 0,1,5 and 10, I decided to upgrade my hdd situation also. Got 3 additional sata3 500gb drives that I'd like to set up, either as raid 0 or raid 5. Also have 3 other Pata drives for backup, etc, giving me 1.5 TB space in addition to the 3 new Sata drives.
My question to you fine people is whether I'd see a decrease in performance going from my 2 drive pata raid 0 setup to a 3 drive sata raid 5 array...
Or are the new drives plenty fast that I should just use them all separately and forego the raid altogther? My main concern is, obviously, video editing. I know I'll have the data security benefit from the raid 5...
Thanks.
Vin
Additionally, is it possible to clone my raid 0 array to a raid 5 array so I don't have to reinstall my OS and apps?

I use raid 0. A minimum of three scsi, but have managed with two eSATA II.
Yes, drives do fail. But not as often as you think. I lose one per year based on daily use. So I replace them after a years use regardless. They're cheap.

If you're worried about avoiding the headache of reinstalling an OS (a different issue), I'd get norton ghost 12 and make a one-time backup to an external usb drive. I've recovered (bare metal) a complete install in less than twenty minutes. The new Ghost 12 comes with an ISO file that will allow you to create a boot CD that houses a recovery OS.