macOS 26 Tahoe: System runs out of application memory (M4 Pro, 48 GB RAM, 2 TB SSD)

See if the problem is present when you boot in safe mode, which disables 3rd party extensions and performs some system cleanup.

Start up your Mac in safe mode - Apple Support

FWIW, I have your configuration (16" M4 Pro MBP, 48 GB memory, 2 TB SSD). I'm running 26.0.1 (from this morning) and upgraded to Tahoe when it launched, and I've had no issues.

geraintfromlondon wrote:

This looks to me like a memory leak in the OS itself. It seems to happen over a period of time. So the temporary fix is to power your machine down when you're not using it and restart it when you are.

And yet...I haven't rebooted my Mac since the 26.0.1 update and my memory usage is perfectly normal.

I'm guessing Apple are aware of the problem and are working as fast as they can to fix it. This is a really embarrassing problem for them - I've been using Mac OS since 1990, and this is the worst system bug that I have encountered by a really long way.

It's not a universal problem, so the main way for Apple to become aware is for people to report issues.

Feedback - macOS - Apple

macOS 26 might have auto-reopen all previously running apps after an update restart, which can instantly eat up a lot of RAM, especially if some apps were already heavy or had background helper processes. Your mac with 48 GB, it usually shouldn’t crash, but memory leaks or aggressive swap usage in Tahoe can make the system hit “out of application memory” fast.

Do a clean restart without reopening apps (uncheck “Reopen windows when logging back in”) and monitor Activity Monitor for any runaway processes before letting apps relaunch automatically

neuroanatomist wrote:

geraintfromlondon wrote:

This looks to me like a memory leak in the OS itself. It seems to happen over a period of time. So the temporary fix is to power your machine down when you're not using it and restart it when you are.

And yet...I haven't rebooted my Mac since the 26.0.1 update and my memory usage is perfectly normal.

Great. That's good. Operating systems are very complicated things. It doesn't follow that everyone's usage is the same, nor that a particular bug will affect everyone. Thus, absence of evidence is not evidence of absence.

I'm guessing Apple are aware of the problem and are working as fast as they can to fix it. This is a really embarrassing problem for them - I've been using Mac OS since 1990, and this is the worst system bug that I have encountered by a really long way.

It's not a universal problem, so the main way for Apple to become aware is for people to report issues.

Absolutely.

Feedback - macOS - Apple

Mail running through all available memory and beyond has been associated with corrupted mailboxes.

Has many mail accounts do you in Mail?

You could try this: go into System Settings->Internet Accounts, and turn off mail for all but one account. Start Mail.

Test. Memory runaway? No? Test with another account.

When you find an account that causes the problem, you can try rebuilding the mailboxes for that account (select, and choose Mailbox->Rebuild)

bschwebel wrote:

Only other 3rd party apps are Chrome and Microsoft 365 but were not open.

Apps are not all that run on a Mac. There are extensions and background processes always running, many of which are from 3rd party software and some of which may not be fully compatible with Tahoe. For example, you mention Chrome. Chrome is a notorious resource hog on Macs. Installing it also installs multiple ‘helpers’ from Google that run in the background, and their purpose is not to help you but to help Google (keep in mind that Google’s primary source of revenue is using your data to drive targeted advertising). Even if you aren’t running the Chrome app, those system extensions are always running in the background. I’d recommend deleting Chrome and all related components.

https://chromeisbad.com

That's just one example. So I will repeat the question from my colleague, Luis Sequeira1, did you test in Safe Mode?

I saw the same problem as well today. Mac Studio ('22) with 64 GB RAM. MacOS 26.

I have never seen this problem before.

Activity Monitor showed that the TV app was using 372 GB of memory! I basically force quit all apps and the system has recovered. No need to reboot.

Billybucks wrote:

I just replaced a macMini late 2018 running on intel with 16GB RAM with an M4 MacBook Pro with 16GB. Everything on the mini was migrated to the Pro. My few extensions and all. The macMini never had this problem. The M4 should eat the macMini's lunch, yet it is running out of application memory! It has to be an OS issue with Tahoe.

And that might be part of the problem. Your 2018 Mac may have had old extensions, and daemons, obviously programmed for Intel, and maybe created several OS versions ago to boot (pun intended).

That is why it is recommended to migrate only the user accounts, and install applications fresh, when migrating to a new mac. Leaves all the potentially conflicting old stuff behind (plus lots of things one may have installed that one is not even aware it's there).

I’ve done the Safe Mode start, and crashed. But in the process, I observed one thing - Mail was always the first thing that “paused” in the Out Of Memory dialog, and “paused” then cascaded through everything else. I could also see the memory usage going up in the Mail app, even as it was paused. Repeated the Safe Mode start, opened Activity Monitor, then opened Mail - and it opened at 16Gb, went to 28 GB, then 48GB and Swapped Memory until it ran me out of Application Memory.

So Mail appears to be the trigger, but I don’t yet know why.

Happened again today. Got home from work and there was a dialog open saying I'd run out of application memory. I opened Activity Monitor and viewed all processes and there were two that were using insane amounts of memory- contextstored and powerd. Both of them using like 35+ GB of memory. I force quit them both and that immediately alleviated the Memory Pressure graph in Activity Monitor but, trying to resume any of the apps listed in the dialog saying that I was out of application memory was fruitless. I had to just go through and force quit them one by one. I haven't rebooted yet but, I'm having a difficult time understanding how this isn't a memory leak in macOS system processes and how it might be a problem with 3rd party software. I hope Apple gets this fixed soon. It's really annoying both times that it has happened.

This looks to me like a memory leak in the OS itself. It seems to happen over a period of time. So the temporary fix is to power your machine down when you're not using it and restart it when you are.

I'm guessing Apple are aware of the problem and are working as fast as they can to fix it. This is a really embarrassing problem for them - I've been using Mac OS since 1990, and this is the worst system bug that I have encountered by a really long way.

Good luck, everyone!

Geraint

NotSoTechnical wrote:

Disagree because everyone reporting this has only one thing in common — Tahoe — and that this is consistently being observed after a period of inactivity/sleep.

People say that every year.

Yes, individual app developers need to maintain compatibility, but the OS clearly needs to do a better job identifying when this issue is occurring, and take some proactive steps to avoid the whole system pausing.

That it's happening across a mix of 3rd-party apps, or a common Apple app, is where it gets hard to identify.

Perhaps this is the infamous Electron problem. Apparently, the cross-platform "Electron" framework uses a private Apple API to do something with the shadows on window corners. Developers aren't supposed to use private APIs. Being private, Apple reserves the right to change them without notice. In this case, it causes significant system problems. I don't know if this is the same issue, but it sounds like it.

These "Electron" apps are very popular with developers who want to make sure they exert the least possible effort supporting Apple platforms.

I see Chrome in your list of apps, it's a notorious resource hog on macOS. I agree that Messages using 51 GB of memory is not normal, but if Chrome is your default browser then Messages is likely pulling link previews from Chrome.

Here's mine, for comparison.

Regarding excessing storage use: do you have a large collection of images for your wallpaper? They seem to have started excessively caching uncompressed bitmap versions of your wallpaper images in several resolutions and aren't clearing the images soon enough. That swallows up all your storage, and to bring it back to this thread, means you can't swap. Reducing the size of that selection seems to mask the problem, although that's not really a solution (feedback has been submitted).

I'm having the same issue. This is happening on both my M2 MacBook Pro and my M4 Mini. Started a day after upgrading both systems from Tahoe 26.01 to Tahoe 26.1. Hopefully Apple will have a patch. You should all report this as a bug to Product Feedback - Apple