: Daisy-Chaining Firewire


krs
Jun 23rd, 2010, 05:40 PM
Since I spent a bit of time recently struggling to get daisy-chaining with Firewire 800 to work and I found many, many people on the net with questions as to what works and what doesn't, I thought I'd just summarize a few points to adderss those questions.

1. You can mix firewire 800 and firewire 400 devices when daisy-chaining, but the whole chain will always drop to the lowest speed, ie FW400 if you have any FW400 devices in the chain.
It doesn't matter where the FW400 devices are in the chain, even if you have FW800 devices connected to the Mac's FW800 port first and the FW400 devices further down the chain, the whole chain will still only run at FW400 speeds.

2. All the devices in the chain have to be powered up otherwise any devices beyond the one not powered up will not mount. That seems obvious to me, but I thought I'd mention it.

3. You can only create a single firewire chain with each FW port on the Mac or firewire hub. My FW800 enclosures have two FW800 ports on them and one FW400 port. I tried 'splitting' the chain by connecting that enclosure to a FW800 port on the Mac and then connecting both another FW800 enclosure and a FW400 enclosure to the other FW800 and FW400 ports respectively. Doesn't work - only the enclosure you turn on first will mount.

4. When buying a firewire enclosure, make sure it has two firewire ports otherwise you must always use it at the end of the chain as the last device. Inexpensive 2.5-inch firewire enclosures often only come with one firewire port.