FYI,
We have tested DV and PhotoJPEG capture/playback with Io and our TriggerFISH FireWire 800 disk drives. Attach Io to the Mac FW 400 port and attach TriggerFISH to our FW 800 PCI card. We have also tested capture and playback of 8 & 10-bit uncompressed footage with two of our drives striped together...don't expect RT uncompressed playback though.
Colin
Technical Support Manager
Humu Systems
http://www.humusystems.com