WTF: Error 6085 + 6086 at every turn

[gormster]

Just got a new Mac Pro as part of an Avid editing system, and installed PT on it. I've been getting the following error messages almost incessantly:

6085 - The audio buffer underflowed. Try decreasing the H/W buffer size.
6086 - The operating system held off interrupts for too long. Try increasing the H/W buffer size.

Every time I change the Playback Engine configuration, it gives a different one. Which one it is seems to have little or no relevance to how I configured the engine.

I've seen a few solutions to this problem on these forums for this problem, and none of them have worked for me. Stuff like changing the firewire port, reducing the number of CPUs and reducing the max CPU load have done nothing. Well, admittedly I haven't tried new RAM modules, but that's pretty extreme and I'd like to think there's another solution.

Is there any other known cause for these errors?

Mac Pro
2 x 2.66 Dual-core Xeon
3GB RAM
Tiger .11
PT 7.4
Mbox 2 Pro

[barstool719]

Did you try everything in the help us help you thread?

Make sure firewire networking, spotlight index, and bluetooth are turned off. I missed those three things when I first setup my mac pro and got those same errors all the time.

make sure your MB2P isnt hooked the the display FW ports. Mine wouldnt playback anything properly if it was.

[The Night Train]

I have a 2x2.66 with 10.4.9 and an 003R..
Connecting FireWire audio interfaces directly to the rear port is key.
Do you have any other external devices, namely FireWire 800 hard drives?
Remove any FireWire 800 devices first.. if that isn't it, then remove any other external devices; USB or otherwise. If the above doesn't apply, try a different (shorter) FireWire cable.

Hope that helps.

[gormster]

Yes, I tried all that stuff. Yes, Firewire networking, spotlight and bluetooth are all off (this mac doesn't even have an airport card). Yes, I hooked it directly into the FW port on the back of the machine. No, I don't have any FW 800 devices. I don't actually have any FW devices other than the MB2P. I'm using the shortest FW cable I own, which is approximately eighteen miles shorter than the one that came with the Mbox. I don't know if I could have fewer USB devices plugged in than I do (need keyboard and mouse!), but I guess I could try taking out the Avid dongle.

Anyway, it's late here, I'm going to bed. Will post results (if any) in the morning.

[DigiTechSupt]

Are you possibly using the power supply for the Mbox 2 Pro? If so - try shutting down and removing it, then disconnect and reconnect the Mbox 2 Pro before restarting the computer.

You only need the PSU if the computer doesn't supply power to the MB2P - using it in addition to computer power can cause erratic behavior.

[gormster]

Nope, not using the power supply.

Okay, I pulled out all my USB devices (hard drive, dongle, tablet) and now it works. I don't know which of those it was, and I guess I'll find out, but thanks to all who suggested things, and especially to whoever suggested that.

[Craig F]

what drive are you recording to?
not system, not firewire, not USB

[DigiTechSupt]

Nope, not using the power supply.

Okay, I pulled out all my USB devices (hard drive, dongle, tablet) and now it works.

It was very likely the tablet. I recall seeing other issues caused by having a tablet plugged in.