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Comment by LoganDark | Hacker News Reader

My Mac has developed the issue of slowing down over time if not rebooted. Heavy GPU use accelerates the decay. It feels just like swapping to disk except it's not - swap usage always 0. I didn't have this issue before Tahoe.

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We may not be far off from finding LLM prompts embedded directly in software. Instead of savefile(data_thing), we might start seeing

  agentcall( claude, data_thing, "please save this file to the user's home directory" )

and the author of that code will pat him/herself on the back then form a habit of telling his/her friends "I am an engineer, I have built over 100 software programs spanning multiple continents".

I already see this behavior out of the tech support class that likes to participate in bureaucratic processes among gen z. The standards and expectations for what is colloquially "engineer", outside of bonafide engineering circles, has really fallen over the last two decades.

The attitude that replacing functions with calls to AI agents is like totally okay in software engineering will eventually seep in too.

https://github.com/cofob/autogenlib

I once worked in L1 support, and because we had to take calls @07:00 sharp (we were the only number a company of 40k people could call) and Windows updates were still a multi-hour endeavor, I stuck to rebooting daily (or shutdown+startup) all devices I use heavily, including MacOS.

Over the past 8 years that has basically solved every bug all my colleagues ran into with MacOS. At some point my boss wasn't getting calendar notifications anymore for a couple weeks, "did you try and reboot?" fixed it in 5m. He later mentioned he hadn't rebooted in 7 weeks.

I don't understand why people treat Apple devices like unbreakable analog AM radios, they're very complex computers like any Windows or Linux machines, with a huge state machine beneath it that is easier to reset daily/weekly than to keep working properly for months.

My Intel Mac didn't need to be rebooted. I would leave it running for months with no issues. Apple devices genuinely used to be that stable.

I get that you can't generally expect things to be that stable. But in my experience they used to be and now they're not!

My M4 Max was probably that stable too until Tahoe, although I rarely left it running for more than a few weeks between updates.

This isn't happening for me, if by "over time" you mean "several weeks" of heavy GPU use without a reboot. Consider the possibility that the root cause is not macOS.

By "over time" I mean that if I run local LLMs or play graphics-intensive games (like No Man's Sky's native Mac port) I can start seeing up to half-second (or longer) delays in switching apps, starting videos and much more with less than 5 days of uptime. Heavy enough usage will reproduce it within a few hours.

If I avoid doing those things, it can last much longer.

I have the 128GB/8TB M4 Max and I'm not even coming close to using up all or even most of the unified memory. I suspect it may be related to some form of fragmentation, though I have no way to know how.

I believe you, just suggesting that the issue may not be quite as general. I have a 64GB Studio M1 Max, so the years of hardware/firmware differences between us may be relevant as well. Hope you find a solution!

It didn't happen to me before the update, so I suspect it must be something about the update or how it interacts with the software on my system. Still, it's one of those issues I have no hope of seeing solved, because at this rate nobody doing development at Apple is actually going to leave a Mac running for days on end...

I was seeing a bug that was very similar to what you describe! I fixed it on my Mac by deleting the .CFUserTextEncoding file in my home directory.

Huh, that file seems to have existed since I first set up the machine! Do you have any more information on this? For me it just contains the bytes `0x0:0x0`. How'd you know to try that and do you know how it worked at all?

Edit: The modification date is actually earlier than the added date -- it looks like the file was transferred by Migration Assistant from my previous machine! Not sure if that's important.

I think I figured it out when I experienced a repeating crash in the drop down control in the network settings, and then looked at the crash report, there was something about localization in the backtrace, so I removed the file in an attempt to fix that and after a logout/ login the weird lag went away too. In my case the file had the value for UTF-8 and something in Tahoe’s text system goes into a loop when that file is present. I’ve had the same file for ages because it fixed a problem with pbcopy/emacs interaction. I wound up working around that issue with an env var once I realized that the file was causing issues.

There's a bug causing NSStatusItems in MenuBar<->WindowServer to enter a continuous redraw loop after a number of hours of uptime which pins CPU at like at least 10-20%. I filed it as FB24528844

    1. WindowServer sends the app a stream of remote-context notifications (CGSDatagramReadStream::dispatchMainQueueDatagrams -> remote_context_notify).
    2. AppKit responds by rebuilding the status-bar window's tracking areas and structural regions (_NSTrackingAreaAKManager _updateStructuralRegionCreateIfNeeded / displayCycleUpdateStructuralRegions, including NSButtonCell _hasRolloverAppearance for the menu bar rollover effect).
    3. That dirties the window, so UpdateCycle/stepTransactionFlush commits a CA::Transaction to the WindowServer.
    4. Another notification arrives and the loop repeats at display refresh rate.

Just so you know, a process pinning the CPU at 10-20% on Apple Silicon doesn't even cause any perceptible impact to multitasking. I've pinned the CPU far higher and not noticed anything like this, so it's definitely not that issue. I sometimes forget workloads are even running because the rest of the system feels so perfectly fine even when the fans are running full tilt.

This causes big pauses and stutters system-wide, which is not consistent with any level of CPU utilization alone.

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