[Park Seward]

You are right. There is not much explanation. One I found from Digi:

Disabling RAID:

RAID is a type of array configuration for your hard drives that can save files between discs or mirror the file to a backup. Unfortunately, this causes erratic and often catastrophic errors with Pro Tools. To disable this feature, find the RAID controller option - it's usually found under the 'Advanced' menu.

I read that an HD user said he was getting 80 tracks from one FW 800 drive so there seems to be little need for a RAID to increase throughput.

However, Glyph says:

Our in-house testing has shown that, in an audio environment, the highest track count can be achieved in JBOD mode. In JBOD mode, using our 48 KHz/24-bit test sessions, the GT 062 supported 80 tracks at edit level 1. At 192 KHz/24-bit, either mode was able to handle 36 tracks at edit level 1. 36 is the max track count we can test using our Pro Tools|HD 2 system.

Above tests were done using Power Mac G5 Dual 2GHz, OS 10.4.8, Pro Tools 7.1, HD|2 Accel, GT 062 connected via FireWire 800.

So how come this works for Glyph???