stevecowley Posted June 2, 2013 Share Posted June 2, 2013 If you don't want any background to my issue, please skip the next 5 paragraphs and start with the heading "IAC DRIVER PROBLEM" BACKGROUND: I have been running a MainStage concert which has quite a few instances of Kontakt in it. I am using Alicia's Keys in most songs, and around 15 other Kontakt patches in various songs. The only other third-party plug-in I'm using is Massive - everything else is stock MainStage plug-ins. I have experienced problems with sudden CPU spikes - the CPU meter within MainStage stays below 50% the whole time, apart from seemingly random spikes. I have monitored the CPU meter in Activity Monitor, and when MainStage tells me there's a spike, all 4 processors are still each running at under 25%. No spike is visible in Activity Monitor. This spike is not repeatable, and happens maybe once every 2 or 3 shows. Unfortunately that's too often as I am working for a major label artist who is playing to a lot of people every night, who I really don't want to hear a nasty crackle from MainStage. It doesn't necessarily happen when there's a lot going on - it can be during a period where there's only piano and nothing else putting pressure on the CPU. I have done plenty of gigs without using Kontakt or Massive, and haven't experienced these sudden spikes. Maybe I've been lucky. But I'm working on the assumption that there is something about using Kontakt and/or Massive that doesn't agree with MainStage. I have searched for a solution to this, but I haven't found anything. I'm using the latest versions of all the software, so if anyone has any suggestions that don't involve using third-party plug-ins outside of MainStage, then I'm all ears! IAC DRIVER PROBLEM: I've set up Kontakt as a standalone instrument, receiving MIDI from MainStage via the IAC Driver. This works as expected, and Kontakt passes audio back into MainStage via Jack (or Soundflower, both seem to work). I have set Kontakt to not pass MIDI through - however MainStage still seems to be receiving MIDI via the IAC Driver as I get a message that alerts me to a MIDI loop. This can be worked around by creating a new dummy keyboard in MainStage's Layout page, and assigning the IAC Driver as the input MIDI channel. I then create a dummy/empty instrument channel within each song, with that dummy keyboard as the MIDI controller for the dummy instrument, and that extra MIDI that's coming in is no longer a problem. Everything is working fine, with one MAJOR problem - after the system has been running for 10 or 15 minutes, the latency of Kontakt instruments has noticeably increased. After an hour, the Kontakt instruments are unplayable, with the latency lasting about half a second. It's definitely the MIDI side of things, rather than audio, as I can see the meters in Kontakt showing the audio being triggered late. So this seems to be either an issue with Kontakt dealing with the MIDI via IAC Driver, or an issue with MainStage receiving a load of MIDI info via the IAC bus which it shouldn't be getting, and getting "clogged up" with it. Can anyone confirm this behaviour on their system? Has anyone successfully used the IAC Driver with MainStage (whether with Kontakt or any other standalone instrument)? [Edited title to reflect the way this conversation is going...] PS. Please ignore the gear list in my signature - for this system I'm using the latest MacBook Pros with solid state drives, the most recent OS 10.8, Mainstage 2.2.2, the latest version of Kontakt, MOTU Ultralite and Micro lite interfaces Link to comment Share on other sites More sharing options...
Jordi Torres Posted June 2, 2013 Share Posted June 2, 2013 IAC DRIVER PROBLEM: I've set up Kontakt as a standalone instrument, receiving MIDI from MainStage via the IAC Driver. This works as expected, and Kontakt passes audio back into MainStage via Jack (or Soundflower, both seem to work). I have set Kontakt to not pass MIDI through - however MainStage still seems to be receiving MIDI via the IAC Driver as I get a message that alerts me to a MIDI loop. This can be worked around by creating a new dummy keyboard in MainStage's Layout page, and assigning the IAC Driver as the input MIDI channel. I then create a dummy/empty instrument channel within each song, with that dummy keyboard as the MIDI controller for the dummy instrument, and that extra MIDI that's coming in is no longer a problem. Why not just set the Hardware Input device of the keyboard already present in your Layout to your MIDI keyboard's port (instead of creating a "dummy" one)? The MIDI feedback loop with IAC occurs because of IAC's nature: anything that goes out a particular IAC bus comes back in the same IAC bus. The hardware Input device defaults to the "All" port (which includes IAC and everything else), this is why you get a MIDI feedback loop. J. Link to comment Share on other sites More sharing options...
CCTMusic Posted June 2, 2013 Share Posted June 2, 2013 Hi I have experienced problems with sudden CPU spikes - the CPU meter within MainStage stays below 50% the whole time, apart from seemingly random spikes. I have monitored the CPU meter in Activity Monitor, and when MainStage tells me there's a spike, all 4 processors are still each running at under 25%. No spike is visible in Activity Monitor. This spike is not repeatable, and happens maybe once every 2 or 3 shows. I think that this could well be an OS issue. Take a look in Console to check if anything is going on with the OS around the time that these spikes occur (mdworker) If you load up a test Concert with internal plugs only to get to your 50% CPU load, do the same issues occur? CCT Link to comment Share on other sites More sharing options...
stevecowley Posted June 3, 2013 Author Share Posted June 3, 2013 Thanks guys, CCT, you may be on to something there. I'm on tour at the moment so I don't really have time to sit and play with a test concert, as the spikes only seem to happen very intermittently - perhaps once every 2 or 3 days. However I do know when the last one happened, so as soon as I get to the venue tomorrow I'll have a look at the Console log and see if it shows anything. If there ends up being no problem running Kontakt inside Mainstage, and I can solve the CPU spike issue, I'll be very happy... Steve Link to comment Share on other sites More sharing options...
stevecowley Posted June 4, 2013 Author Share Posted June 4, 2013 I'll keep the IAC Driver discussion to the other thread. CCT, thanks for suggesting that I have a look in Console for the cause of the CPU spike. Sure enough, something did happen at the exact time of the last CPU spike: 02/06/2013 21:15:55.000 kernel[0]: (default pager): [KERNEL]: ps_allocate_cluster - send HI_WAT_ALERT 02/06/2013 21:15:55.000 kernel[0]: macx_swapon SUCCESS 02/06/2013 21:15:59.000 kernel[0]: (default pager): [KERNEL]: ps_select_segment - send HI_WAT_ALERT 02/06/2013 21:15:59.000 kernel[0]: macx_swapon SUCCESS There doesn't seem to be a "problem" as such - there are no error messages - but clearly whatever is happening here is causing Mainstage's CPU meter to peak. I have been monitoring the CPU usage window in Activity Monitor during the gig, and none of the 4 cores are peaking there. I'm going to do some research into what this HI_WAT_ALERT message means, and whether it's a process that can be disabled without doing any damage. If anyone has any hints, please chime in! Steve Link to comment Share on other sites More sharing options...
CCTMusic Posted June 4, 2013 Share Posted June 4, 2013 Hi I suspect that these messages may be due to a lack of free memory, or a "swap file" error (disk free space)? CCT Link to comment Share on other sites More sharing options...
Maddcow Posted June 5, 2013 Share Posted June 5, 2013 I experienced something very similar during some recent shows and was using an exceptionally "light" concert in terms of plugs etc. I haven't seen the issue again but it was definitely something that hadn't occurred the previous nights and didn't occur the following nights. Everything in my rig was also exactly the same for each show.....no changes at all. Will have to check my logs and see what I can find out. Link to comment Share on other sites More sharing options...
mmm42 Posted June 6, 2013 Share Posted June 6, 2013 Make sure to update to 10.8.4 (it got released this week). This will fix certain common audio drop outs in all audio applications. Link to comment Share on other sites More sharing options...
stevecowley Posted June 6, 2013 Author Share Posted June 6, 2013 Thanks Maddcow and mmm42 for getting involved. Maddcow, I would be very interested to know whether you find anything in your Console log that correlates with your overloads. I have run several tests at the request of someone at Apple, both with and without my audio interface connected. Still getting spikes that correlate with the same "HI_WAT_ALERT" collection of messages in the log. What I did to test it: Using an external computer, I set up a Logic session to send every note at every velocity into every MIDI input for every song, with program changes to select each song in MainStage. In a set of 15 or 16 songs, I'm finding that I get a CPU overload roughly once every 2 runs through the set. Next, I'm going to create some EXS24 instruments that take up the same amount of memory as the Kontakt instruments. My next test will be to remove all traces of Kontakt from the MainStage concert, replace them with the new EXS instruments and run the same MIDI test from Logic. I won't be able to do this until Saturday, but I'll let you know how I get on. mmm42, thanks for the heads up, but I'm not going to update to 10.8.4 at this point. This MainStage concert is critical to a large touring production and although the CPU spikes are annoying, I'm able to flip to a back-up rig as soon as they happen. This is a real pain, and does mean that I have to constantly have my finger on the A/B selector button, but at least I know that's the ONLY problem I'm having. So I'm sticking with 10.8.2 for now as the release notes for 10.8.4 don't mention anything about audio drop outs, and for 10.8.3 they say it fixes "an issue that may cause audio to stutter on 2011 iMacs", which isn't the problem I'm experiencing. If you know more info than is mentioned in those release notes, please let me know! Steve Link to comment Share on other sites More sharing options...
mmm42 Posted June 6, 2013 Share Posted June 6, 2013 So I'm sticking with 10.8.2 for now as the release notes for 10.8.4 don't mention anything about audio drop outs, and for 10.8.3 they say it fixes "an issue that may cause audio to stutter on 2011 iMacs", which isn't the problem I'm experiencing. If you know more info than is mentioned in those release notes, please let me know! Yes, there is a significant audio dropout fix in 10.8.4. Link to comment Share on other sites More sharing options...
CCTMusic Posted June 6, 2013 Share Posted June 6, 2013 Yes, there is a significant audio dropout fix in 10.8.4. Yep.. it does seem to have fixed issues here CCT Link to comment Share on other sites More sharing options...
stevecowley Posted June 6, 2013 Author Share Posted June 6, 2013 Ah ok... perhaps I should give that a go. I can always revert to a backup if it screws something else up! Cheers, Steve Link to comment Share on other sites More sharing options...
coniferous Posted February 6, 2015 Share Posted February 6, 2015 Change the "On Patch Change" preference (General/Parameter Values\On Patch Change) to Keep Current Value. Link to comment Share on other sites More sharing options...
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