maddog there are many different types of raid. On raid-1 (mirroring) read is a bit faster but write slower because all data has to be written on 2 hd's at the same time.
On raid-0 (striping) the data is split on two harddrives, doubling your hd space and almost doubling read/write speed. Bad part with raid-0 is that its not redundant, one disk fails -> you lose all data.
If you have backup and you're looking for some IO power, raid0 is the way to go (if you have ide-raid and only 2 hd's..)
Some boards support also raid0+1 which is a combination of above but needs 3 disks. It's almost as fast as raid0 but as failsafe as raid1.
