System overload

[omar17166]

Have you experimented fiddling with those audio prefs:

• Processing Threads pop-up menu: Choose the maximum number of processing threads used, or have the number of threads set automatically. Automatic is the default setting, and is recommended except when you use other CPU-intensive applications simultaneously with Logic Pro.
   
  
• Process Buffer Range pop-up menu: Determines the size of the buffer used to compute mixes and effects. You can choose between Small, Medium, and Large buffer sizes.
   
  
• Multithreading pop-up menu: Determines whether multithreading is set for playback tracks only, or for playback and live tracks.
   
  
• Summing pop-up menu: Determines whether the Logic audio engine uses double precision or standard precision buffers when summing audio.

 

Thanks for the info Atlas007. I'll surely experiment with these values and see. However, I see the particular case of these overloads appearing only during 1st playback as a bug, and might issue a problem report at Apple. From a previous comment we can see that this particular issue started after 10.4.8.

[omar17166]

 

No. I use the original built in drive (mechanical).. The only externally connected USB drive is one used only for the time machine (backup).

I think that should be the opposite:

• -system (internal) drive: SSD
  -backup (external) drive: mechanical

 

Idealy SSD all the way...

 

Yes, this would definitely be nice. But now the situation is so that I have a mechanical internal drive. To change this I would need a new computer

SSDs were scarce and expensive then (especially at 1TB).

[Atlas007]

Since I don't have that problem and both Lightform and you are sharing the same OSX (and problem), I wonder if updating to Catalina could help?

[omar17166]

Since I don't have that problem and both Lightform and you are sharing the same OSX (and problem), I wonder if updating to Catalina could help?

 

Sure Atlas007. This might help. I was just hoping to be able to postpone such an upgrade a little while longer !!

[omar17166]

A bug report has been submitted

[Daveporter33765]

Has this “first playback system overload” issue ever resolved. I have had this problem for quite some time. I get a system overload on first playback after loading any project, however, no additional overloads occur from that point on. This occurs with both iMacs we have in our two studios. It’s really not much of a problem because as soon as the overload dialog appears and it’s dismissed we can hit play with no problems until the project is closed and reopened.

[des99]

While I don't think I've ever seen this officially confirmed, it *seems* that on loading a new project, the initial playback triggers an optimisation process that best optimises playback for the project - this means the first play has a little bit of overhead (for that analysis) and isn't necessarily optimised ideally between cores.

 

Once you play through the various areas, Logic better handles the processing flows, and subsequent playback is fine.

 

It's only really noticeable when you have a high load, as that extra playback overhead on first playback when things are not ideal, or the allocation of processing cores can make the difference between playing, and not playing until Logic settles down a bit...

[Daveporter33765]

Thank you des99. As you can see in my signature, our iMacs are quite powerful units. I am quite surprised that a project with only a few tracks and only moderate levels of plugin demands exhibit this issue just as much as more demanding projects do.

 

No other DAW exhibits this strange “first playback” overload issue. So, I am sure you are correct, this problem must be related to something unique to Logic Pro.

 

I was really just curious if anyone ever identified a definitive cause for this strange behavior and if a solution was found.

 

As I said in my earlier post, this is really not a major issue since the overload never shows up again after the first playback of a project in any session.

 

Thanks again for your response and great information.

[omar17166]

The answer: the problem is still here. Since then I have upgraded to the max 32 GB and this has not changed a thing. As you mentioned, it is just to live with it.

My feeling is that it is an OS problem. There are similar issues with startups of certain websites. I also noticed that if you take your time between initiating each stage the situation is better: time between bootup and logic launch. Tme between logic launch and loading first project. Time between loading the project and first play.

All workable issues, but quite frustrating. I did issue a trouble report to apple, but as usual nothing happened.

[omar17166]

Oh, and here is an example of apple support when dealing with a genuine problem, solved by using a competitor's product! See attached screenshot.

[des99]

As you can see in my signature, our iMacs are quite powerful units. I am quite surprised that a project with only a few tracks and only moderate levels of plugin demands exhibit this issue just as much as more demanding projects do.

 

I'm only making some guesses, as you'd need a dev to really explain what's happening, but when you hit play and have maybe 20-200 plugins that now have to spin up, Logic doesn't really know how CPU heavy any of them are, or how long they'll take to return the audio buffer. Let's say it guesses and allocates the first 10 plugins to core 1, and the next 10 plugins to core 2, etc. Now while processing, it turns out that plugin 1 was an 8-part Omnisphere instance playing 200 voices, and that used up 80% of that core's processing potential, leaving not much overhead for rendering the other 9 plugins on that core and getting the buffer back in the time required for realtime playback.

 

So next time, Logic could have learned from that, and only allocates a for other, CPU light plugins on the same core, in order that it can do all the work in realtime.

 

That process, or something similar, is what I think is happening, and is more likely to manifest into something visible (ie interrupted first playback) with complex projects, or where you are running CPU heavy plugins - and is dependent on all the usual complex factors.

 

No other DAW exhibits this strange “first playback” overload issue. So, I am sure you are correct, this problem must be related to something unique to Logic Pro.

 

I have less experience with other DAWs, at least in terms of doing anything complicated, and nor do I know how they are architected. Some of them may do something similar, others may not, but I'd just be speculating. It may be that Logic is alone in that it's first guess at how to allocate plugins is assessed so it can do it better once it's learned a bit about the project, and other DAWs just guess every time.

 

I was really just curious if anyone ever identified a definitive cause for this strange behavior and if a solution was found.

 

Nothing confirmed, as far as I've experienced. And I could of course be completely wrong, and there's something else going on instead... You could always try submitting a bug report and seeing whether you get any response on this.

 

Thanks again for your response and great information.

 

You're welcome!