out of curiosity, what kind of speed increase are we looking at? I don't need real world benchmarks, but say how would a 2.0ghz Mac Pro 1,1 with a RAID 0 array stand up to a 2.66GHz Mac Pro 1,1 without a RAID array?
When dealing with a stripe set (RAID 0), you get the
throughput of a single drive in that system
* n (model to be used for RAID, and presuming they're all identical).
So if the intended drive is producing 100MB/s, a set of 2x will produce 200MB/s.
Also, can someone explain redundancy to me in layman's terms? I use Pro Tools and it's very picky about certain stuff... Is RAID a good idea in a bedroom recording studio?
The purpose is to keep a system running even in the event of a drive failure (data is still all there, and is available, though it's running slower). Some levels can provide this, but a stripe set CANNOT. In the instance of a stripe set, if it goes down, the array is done until it's been repaired, and the data
must be restored from a backup. You need backups regardless of the array type used, so please heed this bit of advice. RAID /= Backup. Period.
You can use a second RAID as a backup of a primary RAID, but it's still a backup. The primary (no matter the level used), can get to the point the data is just gone (i.e. RAID 5: a drive fails, you replace it, and the array begins to rebuild, but there's another failure during the process - it's done for, and you would have to restore from a backup).
A redundant array can also save you time as you don't have to repair, reinstall the OS (assuming the OS resides on the failed array), and restore the data (assuming you catch it in time, get a new drive in, and let it rebuild). It would be available during this time, but it increases the stress levels, and is advisable to let the rebuild complete before attempting to use the system.
Ultimately, it's up to you to determine if your data is important enough to warrant a redundant array though. But as a general rule, if you're making money with the system, it's highly advisable (you won't have to re-perform all the missing work, as there can be gaps between the last file updated/created and most recent backup/s).