Level 1

5 points

Logic Pro X random CPU spikes

I've seen this topic posted about a lot, but have yet to find a solution. In my case, I'm running Logic on a powerful new MacBook Pro (specs below) with only one guitar track open. Random CPU spikes make it impossible to record anything without constant pops and clicks. Every couple of seconds there are minor spikes, and then once every 10 seconds or so there is a major one that causes a pop or click.

What I'm running:

Macbook Pro (15-inch, 2018)
- 2.9 GHz Intel Core i9
- 32 GB 2400 MHz DDR4
- Intel UHD Graphics 630 1536 MB
Logic Pro X 10.4.4
Focusrite Scarlett 6i6 audio interface

What I've tried:

Setting buffer size to 32
Closing out all background programs
Checking Activity Monitor for any high CPU tasks
Connecting my MacBook to the power adapter
Updating drivers for my audio interface
Disconnecting my audio interface
Making sure Logic and operation system are up to date
Re-installing Logic

I spent a good chunk of change on my MacBook Pro to avoid overloading the CPU with bigger productions--the fact that it can't handle one guitar track without consistent overloading is really disappointing and I'm hoping I'm just missing something obvious for a fix.

MacBook, 10.14

Posted on Feb 3, 2019 12:38 PM

Top-ranking reply

rpm8va Author

Level 1

5 points

Posted on Feb 6, 2019 5:52 PM

Similar for sure, although as I mentioned in my edit to my last post, my CPU does seem to manage the load for the majority of the time (25% to 33% usage) until it encounters what seem to be random, infrequent spikes.

I will say, after a full restart the CPU is behaving much better after trying all of these solutions. The SMTP and NVRAM/PRAM resets seemed to help a bunch, as well as turning off Wi-Fi, setting processing threads to 12, and switching to Playback mode in Multithreading as you suggested! After playing guitar through the computer for about half an hour, I only had a couple clicks and was able to add Logic's compressor and a limiter on the stereo output without overloading the CPU.

I could mark this as solved, but I feel like there is still some more solutions to give a try if your 2011 iMac is managing those plugins just fine on the 32 buffer.

View in context

Similar questions

28 replies

rpm8va Author

Level 1

5 points

Feb 21, 2019 1:19 PM in response to Pancenter

Not using the MatchEQ plugin--just one track open with Logic's Amp on it.

Hoping that this universal bridgeOS is not a dead end and that Apple eventually fixes the problem. I invested way too much in this computer for it to behave like this.

Thanks everyone for the help so far.

rpm8va Author

Level 1

5 points

Mar 11, 2019 7:20 AM in response to Ylan

Hi Ylan, it's second generation.

Sounds like having a direct Thunderbolt 3 connection is the way to go, which will lower latency and allow me to record on a higher buffer size. The Focusrite Clarett 4Pre is a Thunderbolt 2 though right?

Basically what I've gathered here is that because Logic only assigns one core to the one guitar track I have open (and because there may also be a software issue with Bridge OS that Pancenter mentioned), recording on a 32 sample buffer size is not going to be an option on the latest generation of Macs.

Ylan

Level 1

8 points

Mar 12, 2019 3:24 AM in response to rpm8va

Yes I believe Clarett 4pre has Thunderbolt 2. I have Thunderbolt 3 on my iMac (27", 2017, i5 3.8GHz i5), and the adapter has worked flawlessly. Regarding throughput, I think USB 2 is plenty for any home musician. The latency is, however, higher, but not that much with the second gen.

Now there are other reasons why one would like to have a new sound card (better preamps etc.), but Thunderbolt interfaces are pricey, comparatively, so make sure you can try it out, if the interface proves not to be the problem.

Humbly, Ylan

rpm8va Author

Level 1

5 points

Feb 6, 2019 6:26 PM in response to rzazula

Sample rate is all the way down, 44.1 kHz

Jun 4, 2019 7:32 AM in response to rpm8va

There is a lot of info that seems to point to a background process that causes intermediate spikes on the first core. Apple needs to switch Logics core usage to the LAST CORE not the first core OR enable multi core power on single tracks.

Pancenter

Level 6

14,782 points

Feb 3, 2019 1:01 PM in response to rpm8va

Setting the I/O buffer to a smaller size is only going to make the problem worse.

Set the I/O Buffer to 128 or 256, set Multithreading to "Playback Tracks".

This is a Retina machine? If so, close Logic, open the applications folder and right click the Logic icon, select "Get Info".

There should be a setting to run Logic in Lo-Res non-Retina mode, try that as well. (as a test)

rpm8va Author

Level 1

5 points

Feb 6, 2019 5:15 PM in response to Pancenter

Definitely very similar, if not the same issue! However, I haven't found that switching between the Multithreading modes has not made much of a difference. I have also experimented with setting the processing threads to 12 (seems to help a little) and playing around with the buffer range.

It is a serious question though--as much as it hurts to think that I've just wasted a ton of money, am I overestimating the ability of my MacBook, and 32 samples is too low of a buffer size for the CPU to handle?

EDIT: the only way I'd say my issue is different is that my CPU load usually sits around 25% to 33%, and then once or twice a minute the CPU seems to spike randomly. I will say that all of these attempted fixes have made the spikes far less frequent, but the random big spikes are still my primary concern.

Wilddrums

Level 5

4,286 points

Apr 20, 2019 3:47 PM in response to rpm8va

Just curious, did you update to the last Mac OS version (10.4.4)? Any improvement?

In the release notes there is:

" Improves the reliability of USB audio devices when used with the MacBook Air, MacBook Pro and Mac mini models introduced in 2018 "

This looks like an indirect reference to the Bridge OS / T2 issues but cannot confirm.

Pancenter

Level 6

14,782 points

Apr 20, 2019 7:20 PM in response to rpm8va

All measurements taken with a 64 I/O Buffer.

All CPU speeds are between 2.7 & 3.2gHz minimum 8GB

memory.

IMac mid 2011 running Sierra, Logic 10.4.4

Scarlett 2i4 (2nd gen) round trip latency 8.3ms

Mac Built-In Audio 6.1ms (it's obvious either the OS or Logic has an extra buffer running.)

Windows 7 Thinkpad laptop running Reaper DAW

Scarlett 2i4 (2nd gen) round trip latency 6.1ms

2010 Mac Pro Snow Leopard Logic 9 (last update) (Main recording

system) RME hardware, round trip latency 5.1ms

Windows 7 Desktop with old style RME PCI card (Main mastering) UA DSP card/effects.

RME PCI, round trip latency 4.5ms

Note: All of these older machines can run several tracks of

audio, virtual instruments and effects. The 2010 Mac pro (Logic 9) can run a

considerable amount of tracks at a 32 I/O Buffer. All operating systems are installed

from scratch never installed over an older OS. Only a few 3rd [party plugins

rpm8va Author

Level 1

5 points

Apr 22, 2019 4:37 PM in response to Pancenter

Thanks again Pancenter for the awesome info here. Again, my main beef in this thread has been that my MacBook should be able to do something at a 32 buffer size and it's good that you posted some evidence here of older machines being able to do just that without overloading the CPU.

Even with the UA Arrow and the Thunderbolt 3 direct output, I'm still getting 12.3ms roundtrip on 64 and 10.9ms roundtrip on 32. Those latency times are manageable for me but according to what the Apple rep said, the UA Arrow should have put those roundtrip times closer to the ones you logged on your older machines (in the 4 to 8ms roundtrip range).

Pancenter

Level 6

14,782 points

May 30, 2019 10:35 PM in response to rpm8va

You're making an incorrect assumption. A software Instrument or an Audio input w/efx can only use a single core. What you're seeing when you solo a track is multiple cores being used by the instruments that are muted, not the soloed instrument. The reason it glitches on record is that a single core is overloaded. Because that record track can only use a single core.

https://support.apple.com/en-us/HT201838

this is an older support article but it still is accurate.

Pancenter

Level 6

14,782 points

Feb 7, 2019 1:17 AM in response to rpm8va

Did you try running Logic in Lo-Res mode as I suggested in my first post. If there's a noticeable difference, it could point to a root cause.

Wilddrums

Level 5

4,286 points

Apr 21, 2019 9:37 AM in response to Wilddrums

Oups! Mac OS 10.14.4 I meant.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

Logic Pro X random CPU spikes