OK, gonna get an external HDD (or two or three eventually) and one of the uses will be to hold HDV video while it's being edited in iMovie/(maybe) FCE. Will a FW400 drive show any difference in real word performance (for this task) compared to FW800? FW400 sustains close to 50MB/s, FW800 can hit nearly 100MB/s, SATA150/PATA133 drives can move up to 90MB/s, and SATAII could potentially do 180+MB/s. However, most drives barely max out the SATA150 bandwidth. Now, AIC 1080i60 uses just 14MB/s, so even FW400 should be able to read two streams and write one all at the same time... But, that's just the math. The real world is always different. The other concern would be, of course, that an iMac has one FW400 channel and one FW800, so using the 800 for the drive and the 400 for the camera could help during importing? Anyways, FW400 drives are cheaper and have more features than similar drives with FW800 connections, so it makes sense to only get an FW800 capable drive it it would offer a real world performance difference. Thanks for any input!