Computer crapping out at under 50% of CPU limit in Pro Tools. What gives?

[jsbeeth]

I'm running PT 8 on a digi003 into a pretty brand new IMAC (dual core, 2.66 GHZ, 4GB RAM), and I can only approach about 50% or so of my CPU limit in my sessions before I get an error message saying I'm running out of CPU power (and in the preferences my CPU limit is set to 95%). I sometimes get other errors at this point -- buffer overflows or underflows, but it's usually about CPU power. I record to an external drive but I usually only reach 10-20% or so of that limit, so I'm thinking it's either the computer or Protools.

Since it's a new imac, it only has a firewire 800 port, so I'm using a 400>800 connector from the digi. Might that be part of the problem? Trashing prefs etc doesn't seem to help. I also don't think it's particular plugin compability issues since up until 50% all plugs and everything else runs pretty smooth, and I'm only using current digi made plugs -- digi rack, air bundle, bomb factory bundle, and MPToolkit. Is this just another one of those v8 bugs?

My buffer size is 1024, and lowering the processors used from 2 to 1 doesn't do the trick either -- it only ups the CPU usage in a given session about 30% points or so (e.g., 55% to 85%), at which point the computer legitimately starts to crap out. So it's almost as if using the 2nd processor doesn't actually help, since it freezes in the same spots as it does using just one processor, even though it says my CPU usage is significantly lower with the 2nd one running.

Any ideas???? Thanks for your help!

[JrummerJ]

How is your external drive connected?

[jsbeeth]

USB 2 from the drive into the computer. Though again, the drive itself doesn't seem to be the problem, as it rarely gets beyond 10% or so of its usage limit. Though maybe it's causing other problems? Would I be better off daisy chaining the drive to the 003's firewire port?

[flommer]

Originally Posted by jsbeeth

I'm running PT 8 on a digi003 into a pretty brand new IMAC (dual core, 2.66 GHZ, 4GB RAM), and I can only approach about 50% or so of my CPU limit in my sessions before I get an error message saying I'm running out of CPU power (and in the preferences my CPU limit is set to 95%). I sometimes get other errors at this point -- buffer overflows or underflows, but it's usually about CPU power. I record to an external drive but I usually only reach 10-20% or so of that limit, so I'm thinking it's either the computer or Protools.

Since it's a new imac, it only has a firewire 800 port, so I'm using a 400>800 connector from the digi. Might that be part of the problem? Trashing prefs etc doesn't seem to help. I also don't think it's particular plugin compability issues since up until 50% all plugs and everything else runs pretty smooth, and I'm only using current digi made plugs -- digi rack, air bundle, bomb factory bundle, and MPToolkit. Is this just another one of those v8 bugs?

My buffer size is 1024, and lowering the processors used from 2 to 1 doesn't do the trick either -- it only ups the CPU usage in a given session about 30% points or so (e.g., 55% to 85%), at which point the computer legitimately starts to crap out. So it's almost as if using the 2nd processor doesn't actually help, since it freezes in the same spots as it does using just one processor, even though it says my CPU usage is significantly lower with the 2nd one running.

Any ideas???? Thanks for your help!

You've covered the most common problem sources (plugin compatibility and # of processors)

This isn't performance related, but you should have the HD connected to the Mac and the 003 connected to the HD. Use the 400-800 adapter between the mac and HD. This is a data corruption issue.. If you 003 gets turned off or experiences some other kind of connection issue while the HD is being written to you can trash the directory and possibly lose everything on the drive..

How Many tracks? How many and what kind of plugins? Be specific... Are you sure you don't have any non-digi plugins installed? It doesn't matter it you are using them in a session or not..

There is a "tech support utility" you can download from Digi (do a search in these forums to find a link) that will list all your installed plugins and their versions. You have to run it twice.. The first time it won't return the version #s

[flommer]

Originally Posted by jsbeeth

USB 2 from the drive into the computer. Though again, the drive itself doesn't seem to be the problem, as it rarely gets beyond 10% or so of its usage limit. Though maybe it's causing other problems? Would I be better off daisy chaining the drive to the 003's firewire port?

USB is not supported... FW only

[jsbeeth]

Thanks Flommer, I'll give that a shot, though I thought I remember reading in one of the digi manuals NOT to daisy chain 003's and hard drives (?). And since my computer only has one firewire port/bus, I thought connecting each separately to the comp was the only way. But you're saying this shouldn't help with the CPU limit issue anyway?

[flommer]

No, I thought you were putting the HD last in the chain.

It is not ideal to chain the 003 and HD because of possible connectivity issues like I already described, but with your iMac you really have no choice..

And yes, USB could be the cause of your problems

[jsbeeth]

Hmmm, so just to be clear, does that mean that on ANY computer with only one firewire bus (i.e., every mac *except* the mac pros as far as i know) it's impossible to run a digi 003 in a less-than-slightly-risky way?

[flommer]

Originally Posted by jsbeeth

Hmmm, so just to be clear, does that mean that on ANY computer with only one firewire bus (i.e., every mac *except* the mac pros as far as i know) it's impossible to run a digi 003 in a less-than-slightly-risky way?

You could describe it that way. Plenty of people do this all the time without issues. The HD is the vulnerable part of the chain and by having it first in the chain you are reducing that risk to pretty much the same as simply connecting the drive, anyway. The other thing involved is that any devices on the chain are sharing the bandwidth of that single bus. I don't think that would become an issue till you have multiple drives chained together, OR you were trying to run sessions with LOTS of tracks all on a single FW bus. Apple's recent product decisions are driving this problem more than Digi..

On a MacBook Pro you can add additional FW busses/ports with an express card, but there a re a couple Apple laptops that do not have express card slots either..

iMacs have no expandable card slots of any kind ( as far as I know). All you can do is add more RAM..

[jsbeeth]

Wow, that kinda sucks. But thanks for the info, and I'll give it a try and see what happens.

Btw, what do you mean by "LOTS" of tracks? With the mptoolkit I'm running a max of 64, and I'm not *too* crazy with plug-ins in general. Might this pose a problem? I'm just worried that by switching from a USB connection to a FW daisy chain, I may just be substituting one connectivity problem for another...

Thanks again.