Issues with FCP on intel iMacs with external drives
 

I ran into alot of dropouts and corruption when capturing from tape into FCP -- but only when I had external FW and USB drives connected. Once those were physically disconnected, I haven't had a problem. (dismounting them ain't enough, I had to pull out the cables)

Another issue might be a Leopard 5.2 issue -- while editing, the USB drive went to sleep. Even though FCP is not using that particular drive, it caused a stall, beachball, and then BOOM! FCP bailed out.

What I've learned: Keep all unused external drives and devices unplugged during capture and editing.

This was not an issue with my G4 1Ghz Dual PowerMac -- perhaps the bridge controller for the USB and FW ports has changed in the newer Macs -- I dunno. Anyhoo, thought I'd pass that along.

Don't use USB drives for editing. Though USB 2.0 can reach peak speeds that are slightly higher than FireWire 400, they do not provide the consistent speed needed (even for DV) which results in dropped frames. It has nothing to do with busses or the OS.

Check out this article from Latty Jordan's Final Cut Pro Tips site for good tips on using FireWire drives. Here are a few of the more salient points:

No, never use USB drives for editing -- but even my USB keychain 'thumbdrives' caused havoc.

I also lost a session in FC when a fw drive refused to wake from sleep. Save and save often.

Did NOT know that about Firewire throttling back to the slowest device in the chain. Thanks.

What's a good / cheap firewire800 external hard drive?

Ted: my current setup is a white iMac 2.16GHz w 2GB with 3 external FW400 drives from different manufacturers hooked up and I'm rock solid. Knock on wood...

OSX10.4.1
FCP6.0.3
QT7.4.5

Greg: G-Raid or LaCie are pretty much the "big boys" here, followed by Western Digital MyBooks (which I'm not a fan of for editing).

Watch out with Time Machine as well, if you are using it. Also virus scanning programs.
You may have a program running in the background that is using up the bandwidth although I couldn't say which.

I run a G5 with 4 external FireWire 800 drives. Sometimes there's a USB thumbdrive attached, sometimes a portable FireWire 400, and it never chokes up.

I edit DVCProHD off of a 1TB MyBook FW800 external all the time without problem. They are fragile though.

My opinions about the WD line are easily searchable on here. For me, it's not a matter of ABLE, it's a matter of not being able to control "drive spin down" and having Print to Tapes fail due to spin up time of a drive that went "to sleep". Fix that and I'll happily buy them by the boat load for non-mission critical projects. Also, I have a recent issue with a drive not "waking up" at all, until a full system power down/up cycle.

WD MyBooks
 

are you guys using the "regular" (black plastic?) MyBooks or the brushed metal/aluminum (not sure which it is) MyBook Studio Editions?

The black plastic "cheap as they come" Costco special is what I've been referring to. A great home computer expansion for sure but... <insert my regularly scheduled rant here>

I found a really good, free plug-in made by Digital Heaven called "Disksomnia" which always keeps my external drives "awake" when I'm using FCP.

Digital Heaven - The Hottest Tools for the Coolest Apps

The aluminum MyBook Studio Edition is what I'm using. I don't have a problem with the disk spinning down during projects, but I do have to disconnect/reconnect it sometimes when I leave it mounted, but idle for days.

I vouch for Disksomnia too. It has a info window that pops up upon every boot and can`t be turned off, but... what the hey.

Go into "Energy Saver" in System Preferences and uncheck "put Hard Disks to sleep when possible". That has solved disk spin-up problems on all my Macs running Final Cut.