1) You can stripe 2 or more drives in Windows NT/2k/XP without a additional card. Only spanning is supported in 95/98/ME
2) Note that striped sets perform much better than spanned sets. Spanning simply increases the size of a logical partition, while striping really speeds up the reads by logically spreading the data across the drives. So, when you do a read from a set with three drives, you get 3X the data in the same time as if you read from one. Writes the same way.
3) If you lose any drive in a stripped or spanned set, you lose ALL DATA. Hardware or software mirror (RAID 1) creates redundency so if you lose one drive, the other simply takes over.
4) RAID 0 (Striped set) is faster on the writes than RAID 1 (Mirror) but they are about the same on the reads (FAST!) unless you stripe more than 2 drives.. in which RAID 0 is faster even yet.
5) We have over 50 IBM 20GB ATA100 7200 drives in use without issue. Western Digitals have been giving us issues. Seagate you never know. For a year it will be great, and the next you will experience a lot of failures. I have been using seagates for 15 years and right now IBM is best value IMO.
6) If you get a ATA33 5400 rpm drive and start multitasking with more than 1 thread accessing the drive.. IT WILL CRAWL. ATA100 bandwith with the seek times associated with a 7200 will allow you to record one while watching another. I personally think the 7200 drives last longer as well. (Newer technology)
7) If you really want speed, go Ultra SCSI 3 15K rpm on RAID 0.
8) If you install a spanned set, make sure your swap file is on that set. You will see a major overall performance increase.
Good Luck!