H/W Buffer size settings

[Shelob9]

An associate of mine just got a DP 1.8GHz g5 and an mBox. I was using it the other day and I kept getting the "USB usage is holding off playback try INCREASING the H/W buffer size" so I did then it started giving me the oppisite error, telling me to DECREASE the size. What gives? He says he gets this alot. What can he do to avoid this.

[stackatrack]

I think you need to provide more info here.
Is he running a firewire drive for destination files ?
I've had the same issues with my G4 / 1.4 ghz / Digi002r and the only fix I have discovered is to allocate record & playback to my second internal (non system) ATA drive.
I have three fire wire drives (all 7200 rpm)...same problem with each.
I plan to buy a PCI firewire card and dedicate it to the 002r.
Maybe splitting up the two devices to seperate firewire busses will make this all more stable.

I'm amazed that it all works as good as it does

[davetron5000]

I had this problem wiht a single G5 1.6, using both an 002R and an MBox (the 002R error message was slightly different since it's no USB). My conclusion was that the G5 and pro tools were not compatible. I switched to a G4 and all worked perfectly.

I was able to do stuff on the G5 in this state by selecting "Ignore buffer underruns". This results in somd annoying digital popping during playback and recording, but this noise IS NOT WRITTEN TO DISK, so I was able to get useful tracks.