[Jerry Hofmann] "The stutter is likely caused by the G-raid not keeping up with playback. The I/O gear won't help with this. You need faster drives to get the frames from dropping."
I agree with Jerry. Your iMac is limited however, to either a four bay firewire 800 solution, or to a Thunderbolt solution, such as the promise Pegasus.
David Roth Weiss
ProMax Systems
Burbank
DRW@ProMax.com
http://www.ProMax.com
David is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.