# Logic Pro X not using all cores, and CPU meter fluctuates even when idle



## PeterBaumann (Jan 13, 2016)

As the screenshot shows, even when I've selected an audio track, I'm still not being able to use all of the cores on my system. Any ideas why?

I'm also seeing a lot of fluctuation on the CPU meter 'Audio' section even when logic isn't playing, and is 'idle'. Is this normal? I'd say it goes between 10 and 15% of the overall CPU meter at the top when I'm not touching anything.


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## Nick Batzdorf (Jan 13, 2016)

Even when you select an audio track? 

Somewhere in the back of my mind I remember reading about iMac audio issues. It's fuzzy and I don't know the details - or even whether that's still relevant - but that might be worth searching for.


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## Nick Batzdorf (Jan 13, 2016)

Hang on. I just saw your screenshot.

You're using all but one of your cores. That's excellent - don't worry about it!


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## PeterBaumann (Jan 13, 2016)

Nick Batzdorf said:


> Hang on. I just saw your screenshot.
> 
> You're using all but one of your cores. That's excellent - don't worry about it!


Yeah all but one, I presumed it was supposed to use all! Oh well  

Is it normal to have cpu movement in logic when idle?


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## Nick Batzdorf (Jan 13, 2016)

It is, and I suspect those meters aren't showing exactly what's going on anyway.


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## samphony (Jan 13, 2016)

Never rely on CPU indicators from logic! That's all I can say


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## IFM (Jan 14, 2016)

Looks normal to me. That last core normally doesn't start moving till you really have a ton going on.


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## PJMorgan (Jan 14, 2016)

Yes I agree with everyone else, that looks fine. As for the idle behaviour I usually find that caused by running other apps in the background like mail or safari, although not completely necessary relaunching Logic after a fresh restart ensures nothing else is running & usually leaves the meter totally clear when idle.


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## babylonwaves (Jan 14, 2016)

PJMorgan said:


> As for the idle behaviour I usually find that caused by running other apps in the background like mail or safari, although not completely necessary relaunching Logic after a fresh restart ensures nothing else is running & usually leaves the meter totally clear when idle.


the meter do not take into account what happens outside logic. what you see in Idle is mostly processing in 3rd party plug-ins that happens after the sequencer was stopped. the reason for the buildup in activity after time is a good question though.
as for the last core: logic reserves this core for realtime processing on the selected track and also on the output channel.


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## PJMorgan (Jan 14, 2016)

babylonwaves said:


> the meter do not take into account what happens outside logic. what you see in Idle is mostly processing in 3rd party plug-ins that happens after the sequencer was stopped. the reason for the buildup in activity after time is a good question though.
> as for the last core: logic reserves this core for realtime processing on the selected track and also on the output channel.




That might be the case but I usually find that quitting other apps definitely does help. I just tested it, the Logic meter with no other apps running = minor fluctuation in one core & with 4 other apps running = more erratic fluctuation in 2 cores while idle. I know Logics meter doesn't measure the performance of the overall system but surely having other apps running at the same time puts a bit more strain on the CPU therefore affecting Logics performance which is then shown in the CPU meter.

Usually a fresh restart brings the meter down to zero while idle. I'm not even going to attempt to get into the technical side of it, just saying it how I see it.


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## babylonwaves (Jan 14, 2016)

PJMorgan said:


> That might be the case but I usually find that quitting other apps definitely does help. I just tested it, the Logic meter with no other apps running = minor fluctuation in one core & with 4 other apps running = more erratic fluctuation in 2 cores while idle.


sure I believe you in terms of what you're seeing. from what I understand, Logic can only see what happens inside Logic. Even if the CPU is under more load, the metering couldn't catch that. and the calculating time, the other applications get while Logic is running, is being reduced because those are not "realtime" applications. maybe that's different when Logic is idle. Eventually, it has to do with memory. If real memory (RAM) gets low, there could be an interaction of that kind. It is an interesting topic.


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## PJMorgan (Jan 14, 2016)

babylonwaves said:


> If real memory (RAM) gets low, there could be an interaction of that kind. It is an interesting topic.



I think you might be on to something there, that makes a lot of sense. Safari can be a real memory hog, best practice is to run only Logic while working on a project....easier said than than done though, the proofs right here


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## Hyperwind (Jan 27, 2018)

PeterBaumann said:


> As the screenshot shows, even when I've selected an audio track, I'm still not being able to use all of the cores on my system. Any ideas why?
> 
> I'm also seeing a lot of fluctuation on the CPU meter 'Audio' section even when logic isn't playing, and is 'idle'. Is this normal? I'd say it goes between 10 and 15% of the overall CPU meter at the top when I'm not touching anything.


That’s the solution, I tried it and it works: set Multithreading in Preferences to Playback tracks only.


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