Pro Tools 12.5-6 very high CPU usage with LT-TB

Edited by soundman1402 - October/17/2016 at 8:10pm

Thanks for the response!

What sample rate are you using, what number of channels?

Right, this is a Windows only issue.  PT 12.6 on macOS works without this problem.  A couple of other customers also opened a case about it, so I wouldn't hold my breath that AVID is going to do anything about it.  We have looked at this issue quite a bit and can only determine that AVID changed something between PT 12.4 and PT 12.5 that caused the problem...

There are several people that have reported this to Avid and have posted to threads here at Lynx and on Aivd's forum.  I am seeing exactly the same thing you are seeing.  It would seem to be fairly easy for Avid to work on this if they become interested enough.  Something changed between 12.4 and 12.5 that affects the Lynx AES16e and TB interface.  The problem is not dependent on session content - which would have made this more difficult for them to reproduce and debug.  Like you said, we don't even need to have a session open to see the problem.  I see the same issue with Windows 7 and Windows 10, AES16e or TB, and nothing but the software delivered as part of Pro Tools - no 3rd software of any kind.  I suspect that this is an Avid problem and NOT Lynx as ALL other DAWS I have tried work 100%.  Pro Tools post-12.4 is all that is affected.  And Avid isn't concerned with the problem.  I guess Avid could argue that it has to be a Lynx problem since all other audio interfaces are working with PT 12.5 and beyond.  If not for the fact that PT 12.4 and earlier versions work with the Lynx drivers and what changed that made it stop working are changes that Avid made going to 12.5 - not Lynx - I would be more likely to believe Avid's story that the problem is with the Lynx drivers.  The only other explanation is that Lynx implemented something incorrectly in their drivers that wasn't used by any DAW until PT 12.5.  But I think David/Paul have checked their driver thoroughly.  I seem to recall Paul mentioning at one point that Microsoft had commented that there was an error in the way Avid had implemented ASIO.  If true, that may be what we are now seeing.  Some of us were hoping that Lynx could come up with a work around to make their driver as tolerant as other ASIO device drivers are to the PT implementation.

I just tried the latest version (12.6.1) of Pro Tools.  There was no change regarding this problem.  With no session even loaded the CPU utilization is close to 100%.  I can't load and play a session even at the highest buffer settings.  I went back to 12.4 again and everything works great.  CPU utilization down in the single digits.  

Edited by don4777 - December/05/2016 at 6:37pm

Don,

I was just playing around with some settings within PT12.5 and I checked the "Ignore errors" and the "Minimize additional latency" check boxes in the Playback Engine dialog.  I noticed that even though I had 64 samples set as my ASIO buffer size in PT12.5, it opened our driver with 32 sample buffer size and the CPU meter was acting normally (less then 10% for "The Legion" demo project).  I also limited my I/O to 8 in our ASIO Control Panel. 

Would you mind trying to duplicate my test?

Don,

What is interesting about the "Ignore Errors" checkbox is that we don't report any errors to ProTools.  So I'm not quite sure what the box is supposed to do.  Very strange.

David,

Thanks for doing that.  Avid owes you a cold beverage.

I put in a support ticket for installation of these drivers.  After installing the E or F drivers, I get an error message that the they are unsigned and therefore inactivated by Windows.  I'm guessing this is something specific to my setup, but at this point all of my attempts to get the drivers to work are fruitless.  The B drivers I'm currently using will install just fine.  I'm wondering if I need to do some sort of manual purge of the old drivers to make room for the new ones.  Any advice is welcomed.

Thanks,
- Andre