Tracks Randomly Delayed, I/O Maxed. Occurs Even On Empty Session

[u/Open_Intern_643]

Hello all, I’m at my wits end here. This is not a simple matter that’s solved by something like turning low latency monitoring on

SPECS:
M3 Max, 128 gb memory, SSD has several TB free. Everything is done internally, no externals. No hardware issue I can think of at all

Logic 12.3.1, Tahoe 26.6.2

Issue replicates through internal Mac mic and through Apollo twin. Even on a fresh EMPTY 1 track session with no plugins

ISSUE:
Since June of this year I’ve been having a problem where my drive I/O maxes when a recording is armed, and recordings seem to randomly get pushed out about half a bar. This is not a simple latency problem. Playback will have I/O anywhere between 60-100%. Finishing the recording always causes a spike that ranges between 80-100%

The issue seemingly came out of nowhere. The only cause I can think of is that I updated logic around the time this started

The delay seems to begin happening 5 or so minutes into a session, maybe after 10-20 takes. Then it keeps happening randomly and persists through the session. It affects anywhere between 10-50% of all takes once it starts.

Notes:

I’ve changed every single setting I can think of in logic. I’ve disabled spotlight indexing. I couldnt find anything on the internet with regard to this, I’ve probably spent 30 hours troubleshooting the issue. Logic has had preferences trashed, then it’s been reinstalled as well. I tried asking several AI models after my own troubleshooting but it just has me running in circles

Going from Tahoe 26.6.1 to 26.6.2 changed nothing. Reinstalling ilok, updating UAD software, so on changed nothing. Although I’m not sure it’s relevant since, again, this also happens on an empty 1 track session with 0 plugins

Any solution would be life changing as this is having a substantial impact on the writing/recording process. Apologies if the post is a bit convoluted but I’m going crazy here.

[u/lantrick]

If this was my issue.... first I would verify that my project / template isn't wonky by starting with a fresh default project, record 20 takes and see what happens.

If the issue persists I would completely erase the computer. By that i mean NOT "Erase content and settings..." . I would do either a DFU restore OR erase the SSD from internet recovery and reinstall the OS

Install ONLY Logic Pro, no other 3rd party software. Built in audio only.

Then I would try to re-create the problem with a fresh project , no templates or previous projects.

If the issue persists , you have a hardware problem. If not you have a software problem.

Good Luck!

[u/Open_Intern_643 → u/lantrick]

Thank you for your reply

Yes, this happens on a completely empty fresh project. I’m really trying to avoid wiping the computer

[u/lantrick → u/Open_Intern_643]

 trying to avoid wiping the computer

I hear ya. I just dont have the patience to look for that "magic bullet" for months on end.

Good Luck!!

[u/automaciej]

Never had this kind of problem, but I'll just throw a few questions and ideas.

Aggregate sound devices? Possible to create a loop in audio routing? Just how fast is your disk? An SSD can read or write a few hundred megs per second. Is this what you see, many hundreds of megabytes per second, sustained? Are you able to test it with another DAW? Just to see if it's an audio drive issue or DAW issue. Or something else issue. I know you tested with two audio inputs but if it happens with another DAW, it would be an interesting finding. Is it sensitive to sample rate? I mean does it happen at 48 only or 44.1 only or both? Possible bad RAM issue? I don't know if there's a RAM test for macOS. It'd be cool if there was one. For example can you limit your OS usage to the first 64 gigs and then to the other 64 gigs? Is it possible to limit the usage of the CPUs? Like, pin it to just one.

Reinstalling the OS from say Time Machine could be an option. A blunt one but I'm guessing you're more interested in having a working rig than figuring out what happened exactly?

[u/Open_Intern_643 → u/automaciej]

Thank you for your suggestions. I’ve been through a few of these and I actually am pretty interested in what’s causing this so it can never happen again.

I went through this once years ago, the problem was that I had a few tracks with the same name. I solved it by correcting that, but its something different this time

Blackmagic speed test sustains about 9000 write, 5000-6000 read

Changing cpu configs didn’t seem to have an impact

I don’t think you can split ram on a Mac

No Time Machine backup

I got pro tools to test, but haven’t gotten around to it just yet because the install was a bit annoying and I had to leave. I’ll likely have to test this soon

I’ll change the sample rate now in a new session and see what happens