Problem connecting Firewire device and external HD at the same time

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Problem connecting Firewire device and external HD at the same time

Hi. I'm attempting to record digital audio through a Presonus Firepod A/D interface via a Firewire 400 to 800 cable connected to one of the Firewire 800 ports on a mid-2010 Mac Pro running Snow Leopard.

The problem is that if I have an external HD connected to one of the other Firewire 800 ports on the computer and powered on at the same time, the connection to the Presonus Firewire device is not recognized by the Mac Pro. Not only that, performance of the Mac Pro is affected adversely and System Profiler is unable to list any Firewire devices. If I turn the external HD off, the Presonus device is recognized and listed in System Profiler and the machine runs fine. I'm able to connect two external hard drives via separate Firewire 800 ports on the Mac Pro and both drives mount w/ no problem. It's only when I try to connect one of the external HDs and the Presonus audio device at the same time that the problem occurs.

I used this same arrangement on a PowerMac G5 running Tiger w/ no problems whatsoever. If the 400 to 800 cable is bad, I would think it wouldn't work at all, but it does when only the Presonus Firepod is connected and powered on. Any ideas?

Final Cut Pro 6, Mac OS X (10.6.8)

Posted on Aug 8, 2014 9:05 AM

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stopmotion Author

Level 1

9 points

Aug 8, 2014 3:02 PM in response to stopmotion

Have done more research and apparently this is not an uncommon problem: overloading the Firewire bus when connecting an audio device along with an additional device like an external hard drive. As I understand it now, audio signal is a bandwidth hog and the solution is to get a Firewire PCIe card which will have its own independent Firewire bus and which I'll use exclusively for my audio device.

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