Recording to a new External Harddrive, now "audio device buffer underflowed"

[MSCHAAF]

hey everyone,

I've just started to record with a OWC on-the-go pro 500gb, 7200rpm, oxford 934 chipset harddrive via firewire 800. It is configured correctly in the workspace window as R. when i try to play/record i immediatly get error -6085 that the audio buffer device underfowed, but when i lower the playback engine enough, i immediately get the message that a CPU overload error occurred, error -6101. So depending on my H/W buffer size, I instantly get one of these 2 errors.

While I've gotten CPU overload errors before when recording to my internal drive, I've learned to understand and deal with it. However, the only time I have ever gotten this audio device buffer underflowed message is when trying to record to this external HD.

A little more information: I'm using PT LE 7.3.1 and a macbook pro, 2.4 GHz core 2 Duo with 4 GB of ram. The interface is the Mbox 2 Pro which runs to my laptop's firewire 400 port. The OWC harddrive is connected to my firewire 800 port. I've been told the difference in firewire speeds shouldnt be an issue because the firewire 800 will just automatically compensate and transfer at firewire 400 speeds.

A side question, when you configure your external drive as R in the workspace, should your internal drive be set as T or P and not R? Does this make a difference?

I've also tried disabling bluetooth and my wireless and repaired permissions but I believe the problem lies directly with the external HD.

Any advice is greatly appreciated.

-Dieter

[Sparky1]

What version of operating system are you running?

Sparky

[MSCHAAF]

running OS 10.4.9

and the version of protools I'm running is actually 7.1.3, if it makes a difference