Normally you create the array before any data is on the drives.  The OS is then installed.

OK I’m building a new computer and I need some help.  I want setup RAID 1 because I’m super freaking paranoid of HD failure.  This is the mobo I’m getting and it has built-in RAID but is getting a card a better idea?  I’m probably going with SATA but is IDE a better choice.  Someone help…

SATA= easier to set up and faster than IDE. i’d go ahead and use the onboard, or at least give it a shot. i know sometimes people have issues trying to install a raid set up with the onboard, which is usually fixed with a quick update of drivers. sometimes it requires an updated bios, which is a lil more risky if you dont know what you’re doing.

SATA will work fine.  Promise has a good onboard chip for dual channel SATA RAID.
Will you be running a mirror or a parity setup?

[quote author=“8link”]SATA will work fine.  Promise has a good onboard chip for dual channel SATA RAID.
Will you be running a mirror or a parity setup?

RAID 1.  Now when I get the HD how do I set it up?  Do I do it before I have installed the OS?

I’m going to run my RAID 1 on 2 Maxtor 200GB SATA HDs.  I’ve found a lot on it…

Have you already bought the drives?
It is, of course, my bias but I’ve never had anything but problems with maxtor mechanisms.
A 200GB mirror should afford you enough space and good redundancy, though.
Good luck!