Mix firewire 800 & 400 hard drives

The answer isn't clear, but typically a single FireWire port may run at the speed of the slowest device connected. If this be the case, then it would be better to connect a FW400 device to the FW400 port and FW800 devices to the FW800 port. But it's also possible that a FW800 port will operate at both speeds if FW400 and FW800 devices are connected. But this may be limited by transfers between the devices. That is moving data between a FW800 and FW400 device on the same bus will force the transfer rate to the slower speed.

In your case the best thing to do is simply experiment to find out.

Please check the documentation that came with your external drives or the website of the supplier. I know my Rocstor external drives have two FW800 connectors, a FW400 connector, and a USB connector. I connect one drive to the FW800 connector on the computer and piggyback the other FW800 drive in the other FW800 connector on the first external drive. I would do the same if I had a FW400 drive, so I would go with plugging it into the second FW800 connector with the FW400/FW800 cable as you suggested. Unless someone has verified you can plug the second FW400 drive into the first drives FW400 connector, I would not do it. The other response you received is correct, all drives will connect at the speed of the slowest drive in a piggyback arrangement, i.e. FW400 speeds. Sure would have been nice if Apple included a second FW800 connector on the new iMacs... maybe next year's model?

If that G-Drive external that you use for Time Machine happens to also have a USB 2.0 connection, you may want to consider using USB for that drive to take the load off the FireWire port. Time Machine does not require an ultra-fast connection (it works to a Time Capsule over AirPort), and you have more USB ports. My Time Machine backup volume is on a USB 2.0 drive (and it even connects through a hub), and it works fine for that purpose.

Can I change my mind? I just read the manual again that came with my Rockstor 850 and it says the only restrictions on daisy-chaining are
(1) that only one cable is used to connect to the computer and
(2) it seems many other devices including other drives or Firewire devices such as camcorders can be daisy-chained as long as they use Firewire connections.

When I first read this long ago, I thought everything needed to be connected via the FW800 connectors on the drives, but rereading it, it seems any Firewire device will do going into any Firewire connector as long as the path ends with one FW cable connecting to the computer. I would still check your documentation with your drives of course. as they were not Rocstor.

I should also point out that when I daisy-chain my external drives they are powered drives not drawing any power from the FW800 connectors. When I tied to daisy-chain my external iSight camera as the end of the chain, it did not work as it probably needs more power than the external drive provides for the connector. My camcorder should still work, especially when the camcorder is powered by its DC power source. since that will supply power to the FW connection from the camera. Have not tried that yet though but I'm confidant it will work. Has anyone else successfully daisy-chained their camcorder to an external drive connected to the new iMac FW800 connector?

There have been many substantiated problems with connecting a FireWire camcorder in a chain. Some will not work with any other device on the bus. This has been argued as a problem with the implementation of the FireWire port or a problem with the camcorder's implementation.

Just spent quite a while in the Final Cut Express and Final Cut Pro discussion group and the video guru Tom Wolsky (I hope that's the correct last name) has pretty much instilled the fear of the Lord in me with regard to daisy-chaining a Canon HV20 camcorder wiith my external Rocstor FW800 drives.

The safest thing many people say is to connect any Firewire camcorder directly to the computer and not daisy-chain it. Even adamant about removing any other Firewire connections on the same computer using the computers' Firewire ports (Firewire cards okay on Mac Pros) as they share the same Firewire bus. Also strongly recommends turning off Time Machine as well so no interruptions to the time critical importing of video. That means on the iMac, I'll temporarily remove the Firewire hard disks and import to the internal iMac drive. I don't want to risk screwing up the video import or worse, the external hard drives...

Hi Rick,

You'll probably find you drop frames if on the same firewire bus as your g-raid. I had this problem with my g-raid and Canon XM2, installed a second firewire 800 card in my Power Mac and then all was well. Personally I'd import from your camera to the internal drive (g-raid disconnected) then once the import is complete, reconnected g-raid and copy content across. It's a bit of a faff, but you're less likely to have issues. Another possibility would be to migrate to an iSCSI storage solution... probably a bit more pricey than you wish though.

Rob.