Latest post Fri, Jun 6 2014 5:40 PM by S.Clements. 2 replies.
Page 1 of 1 (3 items)
Sort Posts: Previous Next
  • Fri, Jun 6 2014 12:35 PM

    • S.Clements
    • Top 150 Contributor
    • Joined on Sun, Jul 3 2011
    • London, United Kingdom
    • Posts 812
    • Points 10,765

    CoreAudio Underrun - Is computer "leaking" ram?

    Hi,

        I've had this problem forever and can never seem to find a suitable explanation for it.  Almost on a daily basis, I will be editing and all of a sudden I will get a Coreaudio Underrun error that will prevent me from playing footage in the timeline. The only way to get rid of it is to restart the computer.  The frequency is about once a day, unless I watch a lot of streaming Internet video, play quicktimes or listen to music, in which case the underruns come on more frequently.

          I'm not an expert on the inner workings of computers, but does this point to a sort of "leaking" of Ram?  If not, why would the restart fix the underrun?  Is there any way to prevent the leak?  I had a similar problem with After Effects where I had to download a program called "Purge".  Purge sat in my tool bar and whenever I ran into a ram problem with After Effects, I would press the button and all would be fine.  Unfortunately, Purge does not fix the problem with Avid though.  Does anyone out there know how to stop these CoreAudio Underruns? 

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
    Filed under: , , ,
  • Fri, Jun 6 2014 3:55 PM In reply to

    • ppohio
    • Not Ranked
    • Joined on Sat, Jan 28 2012
    • Posts 111
    • Points 1,435

    Re: CoreAudio Underrun - Is computer "leaking" ram?

    I don't know what that issue is, but something has been wrong with Avid and the Mac and audio since around version 5.5 or 6 of MC and Mountain Lion on the Mac side. I have problems wth this and the dreaded AMPI Subsystem error since that time. The latter is a real killer as the only way to deal with it is a reboot.

    For the CoreAudio Underrun error, I've been able to usually solve that by quitting Avid, opening Activity Monitor and quitting CoreAudio. It will restart the process automatically. Then you should be able to open Avid back up and get back to work. 

    You can check for a memory leak with a program like iStat Menus, but I don't think that's the problem. I've tested this in numerous configurations, including never running any other programs, just Avid, closing it after each edit session, not using any RTAS audio effects, etc and no matter what, after a couple days I'm playing some footage and bang AMPI Subsystem error and I have to reboot.

    Hopefully that helps, I've posted about this several times in various threads and have given up on it ever getting fixed. 

    Macbook Pro 15" 2.2Ghz, Intel Core i7, AMD Radeon HD 6750M, 8GB RAM OS X Lion 10.9.1 Avid Media Composer 7.0.3 [view my complete system specs]
  • Fri, Jun 6 2014 5:40 PM In reply to

    • S.Clements
    • Top 150 Contributor
    • Joined on Sun, Jul 3 2011
    • London, United Kingdom
    • Posts 812
    • Points 10,765

    Re: CoreAudio Underrun - Is computer "leaking" ram?

    Thanks for all the info, ppohio.  It's good to know it's not a problem unique to myself.  Good tip about the Activity Monitor!

    Avid Media Composer 8.3.1 Macbook Pro (Retina, 15-inch, Mid 2014) 2.8 GHz Intel Core i7, 16GB Ram Mac, OS 10.10.2 [view my complete system specs]
Page 1 of 1 (3 items)

© Copyright 2011 Avid Technology, Inc.  Terms of Use |  Privacy Policy |  Site Map |  Find a Reseller