A technical support community for Apple Logic Pro users.

 
EverVale
Topic Author
Posts: 21
Joined: Fri Jan 11, 2019 6:17 pm

Flex/Follow Tempo in Sampler CPU Usage issue

Tue Jul 27, 2021 10:12 am

Hello,

It appears that Flex turned on in the sampler is now causing over 20% spike in Cpu usage in LPX 10.6.3. I was on Catalina and now Big Sur and both have the same result. When I turn off Flex it goes away but the moment I turn on flex in Q-Sampler/Sampler the CPU spike returns. It gets even worse when I lower the buffer but still remains on the highest setting.

Is any one else having this issue or even noticed it? If possible, can someone test it out to see if it's just my end or a Logic 10.6.3 issue. I would kindly appreciate it.
LPX 10.6.3
Big Sur 11.5
iMac i7(late 2015)
32gb ram
Apogee Symphony IO mkII
 
User avatar
Atlas007
Posts: 10070
Joined: Mon Dec 14, 2009 11:58 pm
Location: Montreal

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Wed Jul 28, 2021 1:43 pm

Have you uodated your drivers?
I would also try increasing the I/O buffer size instead.
BTW, what sample rate are you working with?
LogicPro 10.6.3, MainStage3.5.3
MBPro 17", Core2Duo, 8G, OSX 10.12.6
MacPro, Xeon 6Cores, 64GB, OSX 10.15.7
ULN8, MOTU MIDI TP-AV, C4, MCU Pro, KorgNano, Novation SLMkII
AAS, NI, Celemony, Spectrasonics, Korg, Arturia, etc...
PC, iPadPro 5th gen 12.9”(Duet D., V-Control & LogicRemote), AtariST(Notator SL), Several vintage gear
 
EverVale
Topic Author
Posts: 21
Joined: Fri Jan 11, 2019 6:17 pm

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Thu Jul 29, 2021 8:25 am

Hi,

Yes, my symphony drivers are up to date.I work in 96k but it's never happened in previous version of logic. I have also tried all buffer settings and they all have a spike when triggering one key in the Q-Sampler. At 1024 it still spikes a good amount, like 15% but obviously worse the more I lower the IO buffer. If I use/play any other software instrument it's ok, no spikes but the moment I use the Sampler and turn on Flex/Follow Tempo, the spike happens in any IO buffer setting.

Here is how to reproduce it:
1. Select an audio apple loop from the browser.
2. Drop it in the Quick Sampler
3. Turn on Flex
4. Play any key
5. Spike jump between 15-25%

My Symphony mkII drivers are the latest so to me it point to the Sampler being the culprit at the moment. Nothing I can do I guess but would like to see if anybody else gets this problem by using the steps above. I would appreciate it.
LPX 10.6.3
Big Sur 11.5
iMac i7(late 2015)
32gb ram
Apogee Symphony IO mkII
 
User avatar
Atlas007
Posts: 10070
Joined: Mon Dec 14, 2009 11:58 pm
Location: Montreal

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Fri Jul 30, 2021 1:36 pm

I could try (when I make it to the studio), but my mileage may differ since my system is quite different than yours.
BTW, 15-25% increase doesn't seem that much if it doesn't go beyond the maximum range... Besides the visual cue on the CPU, do you have other audible ensuing issues?
LogicPro 10.6.3, MainStage3.5.3
MBPro 17", Core2Duo, 8G, OSX 10.12.6
MacPro, Xeon 6Cores, 64GB, OSX 10.15.7
ULN8, MOTU MIDI TP-AV, C4, MCU Pro, KorgNano, Novation SLMkII
AAS, NI, Celemony, Spectrasonics, Korg, Arturia, etc...
PC, iPadPro 5th gen 12.9”(Duet D., V-Control & LogicRemote), AtariST(Notator SL), Several vintage gear
 
EverVale
Topic Author
Posts: 21
Joined: Fri Jan 11, 2019 6:17 pm

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Fri Jul 30, 2021 4:22 pm

Cool, I would appreciate it. I just want to determine whether it's Logic or my Symphony's drivers causing that.

It's not so much the 15-25% that is affecting but a few audio halts(CPU overload messages) when playing my midi keyboard with the Sampler. I only noticed the visual cpu spikes and the CPU overload messages after upgrading to the latest Logic pro version 10.6.3.

In the meantime, I will continue to troubleshoot in hopes of a solution.
LPX 10.6.3
Big Sur 11.5
iMac i7(late 2015)
32gb ram
Apogee Symphony IO mkII
 
User avatar
Atlas007
Posts: 10070
Joined: Mon Dec 14, 2009 11:58 pm
Location: Montreal

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Fri Jul 30, 2021 6:57 pm

EverVale wrote:
Cool, I would appreciate it. I just want to determine whether it's Logic or my Symphony's drivers causing that.
I think that one quick way to check if the Symphony's driver are involved would be to change the I/O Devices in the Audio prefs (from Symphony to System or Built-In... depending of BigSur's nomenclature).

EverVale wrote:
It's not so much the 15-25% that is affecting but a few audio halts(CPU overload messages) when playing my midi keyboard with the Sampler. I only noticed the visual cpu spikes and the CPU overload messages after upgrading to the latest Logic pro version 10.6.3.

In the meantime, I will continue to troubleshoot in hopes of a solution.
Keep us posted!
LogicPro 10.6.3, MainStage3.5.3
MBPro 17", Core2Duo, 8G, OSX 10.12.6
MacPro, Xeon 6Cores, 64GB, OSX 10.15.7
ULN8, MOTU MIDI TP-AV, C4, MCU Pro, KorgNano, Novation SLMkII
AAS, NI, Celemony, Spectrasonics, Korg, Arturia, etc...
PC, iPadPro 5th gen 12.9”(Duet D., V-Control & LogicRemote), AtariST(Notator SL), Several vintage gear
 
User avatar
Atlas007
Posts: 10070
Joined: Mon Dec 14, 2009 11:58 pm
Location: Montreal

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Fri Jul 30, 2021 7:18 pm

EverVale wrote:
Hi,

Yes, my symphony drivers are up to date.I work in 96k but it's never happened in previous version of logic. I have also tried all buffer settings and they all have a spike when triggering one key in the Q-Sampler. At 1024 it still spikes a good amount, like 15% but obviously worse the more I lower the IO buffer. If I use/play any other software instrument it's ok, no spikes but the moment I use the Sampler and turn on Flex/Follow Tempo, the spike happens in any IO buffer setting.

Here is how to reproduce it:
1. Select an audio apple loop from the browser.
2. Drop it in the Quick Sampler
3. Turn on Flex
4. Play any key
5. Spike jump between 15-25%

My Symphony mkII drivers are the latest so to me it point to the Sampler being the culprit at the moment. Nothing I can do I guess but would like to see if anybody else gets this problem by using the steps above. I would appreciate it.

Yes there is indeed a CPU surge, in my case up to 50%.
I couldn't confirm that also occurred in previous version though...
LogicPro 10.6.3, MainStage3.5.3
MBPro 17", Core2Duo, 8G, OSX 10.12.6
MacPro, Xeon 6Cores, 64GB, OSX 10.15.7
ULN8, MOTU MIDI TP-AV, C4, MCU Pro, KorgNano, Novation SLMkII
AAS, NI, Celemony, Spectrasonics, Korg, Arturia, etc...
PC, iPadPro 5th gen 12.9”(Duet D., V-Control & LogicRemote), AtariST(Notator SL), Several vintage gear
 
EverVale
Topic Author
Posts: 21
Joined: Fri Jan 11, 2019 6:17 pm

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Sat Jul 31, 2021 9:09 am

Thanks for the confirmation. I thought I had it bad but you're getting 50%. It seems wrong that flex in the Sampler is using that much cpu but not when turning it on in the tracks. I will submit a bug report since this is the only thing I can assume.

I have an extra ssd that I can re-install Mojave to get a previous version of Logic for testing. I will report back with the results.
LPX 10.6.3
Big Sur 11.5
iMac i7(late 2015)
32gb ram
Apogee Symphony IO mkII
 
User avatar
Atlas007
Posts: 10070
Joined: Mon Dec 14, 2009 11:58 pm
Location: Montreal

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Sat Jul 31, 2021 1:36 pm

Perhaps the new versions of logic are geared toward the new M1 optimisation, which leaves the Intel Mac performance decreasing...
LogicPro 10.6.3, MainStage3.5.3
MBPro 17", Core2Duo, 8G, OSX 10.12.6
MacPro, Xeon 6Cores, 64GB, OSX 10.15.7
ULN8, MOTU MIDI TP-AV, C4, MCU Pro, KorgNano, Novation SLMkII
AAS, NI, Celemony, Spectrasonics, Korg, Arturia, etc...
PC, iPadPro 5th gen 12.9”(Duet D., V-Control & LogicRemote), AtariST(Notator SL), Several vintage gear
 
EverVale
Topic Author
Posts: 21
Joined: Fri Jan 11, 2019 6:17 pm

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Sat Jul 31, 2021 5:09 pm

Good thinking! Didn't even cross my mind and it's very possible. I'll have to live with it meanwhile support gets back to me or a new update comes out.

Thanks again and cheers!
LPX 10.6.3
Big Sur 11.5
iMac i7(late 2015)
32gb ram
Apogee Symphony IO mkII
 
kiotozane
Posts: 106
Joined: Fri Nov 04, 2005 1:23 am

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Sun Aug 01, 2021 12:38 am

Hello! I would say this is "expected", did you have wildly lower CPU use before? I've always seen strong increase in CPU use with Flex.

I just now got a maxed out Mac Mini, I just tried if they had optimized it there, loading single looped sample into Quicksampler:

Max polyphony 64, when all notes playing
Regular mode CPU use approx 10% of one core
Flex mode CPU use approx 50% of one core, so ~5 x increase in CPU

Btw I also quickly tried Alchemy in Granular, and got same result as Flex, at 25% core use at the max 32 voices polyphony. Which would be 50% at 64. So to me, Flex is using same CPU as Alchemy granular, which is also what I would expect.

My experience from many many samplers over the years, is that shifting to any kind of realtime timestretching algorithm always comes with a sizable CPU cost over traditional faster/slower playback. Sampler and QuickSampler is in then in my experience here kinda modest (a 5 x increase), most other samplers have around 10 and sometimes up to 20x increase (hello Kontakt!) in CPU use when shifting from regular traditional faster/slower playback. They also quite often restrict the polyphony hard, LPX doesn't.

PS this was highly informal tests just eyeballing the meters.
LPX & macos Big Sur latest, MBPR 2013/2016/2019/Mac Mini M1, RME UCX & BF
 
EverVale
Topic Author
Posts: 21
Joined: Fri Jan 11, 2019 6:17 pm

Re: Flex/Follow Tempo in Sampler CPU Usage issue

Tue Aug 03, 2021 10:33 am

Ok, so took a full day to test this out in Mojave with the same setup and to my surprise, it was still happening with LP 10.5.1.

Kiotozan - you're spot on in that it's normal behavior for high cpu usuage when flex is active while playing midi live. I also tested Alchemy and got the same result. I guess I'll just have to make sure to have my buffer at 1024 when playing live midi. Can it be improved by the Apple Logic team... of course, and it would be nice.

Tip and workaround solution:

I did however find a solution to avoid having to activate flex in the Sampler.

1. Drag the audio/loop to your workspace
2. Adjust your audio/loop to the tempo that you want
3. Drag that audio clip to the left into the Q/Sampler
4. viola! You now have it sync to the project tempo without the need to activate Flex in the sampler.
5. Repeat the steps above to change to a different tempo.

This will only work if you drag your audio/loop to the workspace first before dragging it in to the Q/Sampler

Thank you guys for the help and your patience.

Cheers!
LPX 10.6.3
Big Sur 11.5
iMac i7(late 2015)
32gb ram
Apogee Symphony IO mkII