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Yeah, Sptzz's machine should be flying with Tahoe like a Formula 1 car. There's no reason a M3 Max with 48GB should be experiencing any UI stutter. I appreciate everyone's input on this as I do eventually want to upgrade to Tahoe for the Spotlight features. Keep up with the updates everyone!
yes the spotlight feature attract me much
 
M1 Pro, 16GB RAM.
It stutters, a lot, it's the first time in a lot of years that an UI stutters enough to bother me.
Tried disabling transparency on Accessibility settings, no difference.
Meh, it'll be solved sooner or later. Never changing my hardware because of this, no doubt.
 
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I suspect a lot of the reported performance problems are from this Electron bug. Electron is using a private API that's causing a lot of window server overhead. Lots of things are Electron: Discord, Slack, Spotify, Unity Hub, etc.
There's a workaround in the GitHub issue thread. It won't persist a reboot, and you do have to restart any Electron application. Search processes in Activity Monitor for "(Renderer)" to find them if you aren't sure if you caught them all:

Code:
launchctl setenv CHROME_HEADLESS 1

If you want to undo without a reboot, it's just:

Code:
launchctl unsetenv CHROME_HEADLESS

This workaround will ultimately remove window shadows on Electron apps, which is where the problem lies.

Before this bug turned up, I was worried Apple had bitten off more than they could chew with fill rate / memory bandwidth, so hopefully this is a big part of it instead...

Wow, after trying this fix, I found that the shadow is the cause of stuttering. To test this, just open 5 Safari windows, click on the desktop, and click the desktop again. You’ll notice the animation stuttering. (Yes, only 5 windows cause an issue.)

However, when you open multiple windows of Edge or Visual Studio Code, after run the disable shadow command and the animation returns to normal without any stuttering.
 
I suspect a lot of the reported performance problems are from this Electron bug. Electron is using a private API that's causing a lot of window server overhead. Lots of things are Electron: Discord, Slack, Spotify, Unity Hub, etc.
There's a workaround in the GitHub issue thread. It won't persist a reboot, and you do have to restart any Electron application. Search processes in Activity Monitor for "(Renderer)" to find them if you aren't sure if you caught them all:

Code:
launchctl setenv CHROME_HEADLESS 1

If you want to undo without a reboot, it's just:

Code:
launchctl unsetenv CHROME_HEADLESS

This workaround will ultimately remove window shadows on Electron apps, which is where the problem lies.

Before this bug turned up, I was worried Apple had bitten off more than they could chew with fill rate / memory bandwidth, so hopefully this is a big part of it instead...

Of course. Electron. That framework is a cancer that needs to die.

I rolled my eyes so hard when I read this:

Hey folks, anyone experiencing this issue can you please raise a Feedback (via Feedback Assistant) with Apple.

[...]

We need a lot more to go on and this is likely a macOS issue.
Typical reaction from Electron framework developers. Blame everyone else.
 
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M1 Max MBP running macOS Tahoe. I'm just browsing the internet with Safari, checking email, watching some YouTube videos with Safari, and other basic activity, and my GPU activity keeps spiking and it remains elevated for extended periods of time making my machine very warm, and it's draining my battery a lot faster. Even thought Activity Monitor shows normal GPU percent and activity, I'm seeing GPU activity in the range of 36% - 76% in the GPU History window and in Stats. I don't have any third party apps running except for Stats.app. I truly hope there is a fix for this coming soon. This MBP being four years old now, it makes me a little uncomfortable running it all day with the GPU activity staying elevated like this.

UPDATE: I'm not having this issue anymore. I'm not sure if the macOS 26.0.1 update helped or not, but all is good now.
 
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Of course. Electron. That framework is a cancer that needs to die.

I rolled my eyes so hard when I read this:

Typical reaction from Electron framework developers. Blame everyone else.

I suspect a lot of the reported performance problems are from this Electron bug. Electron is using a private API that's causing a lot of window server overhead. Lots of things are Electron: Discord, Slack, Spotify, Unity Hub, etc.
There's a workaround in the GitHub issue thread. It won't persist a reboot, and you do have to restart any Electron application. Search processes in Activity Monitor for "(Renderer)" to find them if you aren't sure if you caught them all:

Code:
launchctl setenv CHROME_HEADLESS 1

If you want to undo without a reboot, it's just:

Code:
launchctl unsetenv CHROME_HEADLESS

This workaround will ultimately remove window shadows on Electron apps, which is where the problem lies.

Before this bug turned up, I was worried Apple had bitten off more than they could chew with fill rate / memory bandwidth, so hopefully this is a big part of it instead...


Nice hunch, but I don't use Electron apps and it still happens.

As a matter of fact, I tried disabling transparency systemwide (via Accessibility), no difference.
 
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Nice hunch, but I don't use Electron apps and it still happens.

As a matter of fact, I tried disabling transparency systemwide (via Accessibility), no difference.
me neither; disabling transparency makes no difference
 
but I don't use Electron apps

I bet you do. Open Activity Monitor, View -> All Processes, search for "Renderer".

Is that the definitive way to tell if an app uses Electron? Brave for example has a process named Renderer but my understanding is that it is not an Electron app (in the common usage of the phrase -- given the ideas involved, I'm guessing there is some overlap in the code bases).
 
Is that the definitive way to tell if an app uses Electron? Brave for example has a process named Renderer but my understanding is that it is not an Electron app (in the common usage of the phrase -- given the ideas involved, I'm guessing there is some overlap in the code bases).

Electron is a packaging of Chromium, which Brave uses, so it'll still have the three helper processes (GPU/Plugin/Renderer). My understanding is that this issues stems from Electron itself, though, not Chromium, so it shouldn't be affected.

One fast way to check is to open the .app package (right-click, Show Package Contents). The Contents/Frameworks folder will have Electron Framework.framework:

Screenshot 2025-09-29 at 04.12.56.png
 
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Dammit. You're right. I didn't realize that Signal was Proton-based.

It's a very weird bug! It seems like WindowServer logic in macOS 26 changed so that even an empty _cornerMask override triggers the issue. Every Electron app causes it to happen, so how did Apple not notice? Or maybe they did and felt justified because it was marked private in the first place, who knows.

Also, yeah, a surprising amount of things are Electron these days. I usually think of it as desktop versions of things fully available on the web (Slack, Discord, even Spotify). But tools like Obsidian, Bitwarden, etc, are also Electron...

Electron itself has merged a fix, but will take awhile to spread around. I imagine Apple themselves will have some sort of fix included in 26.1, maybe even a 26.0.1...
 
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Handy terminal command: find /Applications -name "Electron Framework.framework"

Additional apps: 1Password, Dropbox and balenaEtcher.

DS
 
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Anyone try the .01 update today? Any difference in performance? I noticed an improvement on my M3 MacBook Air, but looking to see any fixes for the M1 16" MacBook Pro..
 
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Anyone try the .01 update today? Any difference in performance? I noticed an improvement on my M3 MacBook Air, but looking to see any fixes for the M1 16" MacBook Pro..
same question. can't wait to see if any improvement.
 
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M1 mini 16gb. The one area where Tahoe is way worse than all previous versions is reopening apps on start up. It used to be very fast. I have about 6 windowed apps that I always have opened and it was bang bang bang. Now it takes an additional 20secs or so from the time the desktop comes up to the time the windows reopen.

26.0.1 hasn't improved this
 
same question. can't wait to see if any improvement.
I installed .01 and I have noticed some improvements, but still needs work. The UI seems to glitch a little less and things seem a little tighten up. But...still needs work.
 
I'm running a M1 MacBook Air with 16GB of DRAM and 55GB free on the startup drive. I'm also not seeing any unusual background loading on the CPU, GPU, or memory. That said, I also don't use or install any third-party extensions to any of my systems or Apple apps (well, I've installed Downie under Safari).

No serious problems with performance AFTER boot, but the boot process is quite slow (reminds me of my Windows 10 PC on a Core i7). That said, Safari seems to have issues that did not change or get fixed after I updated to 26.0.1.

In Safari and on several different web sites the hot links stop working and on other times the page does not update and/or goes completely white/blank after being placed into the background (on a tab). The only way to fix this behavior after it first occurs is to open another tab on the same website or reboot Safari. Interestingly, if you do a copy all on one of these blank pages and then paste that into TextEdit you do get the text from the website, but the display in Safari is still totally blank.

The website where the hot links stop working most often (greater than 50% of the visits, after the first one or two working links) is CNN.com. When the links stop working they don't even get highlighted when you place you mouse over the link. It's almost like Safari is losing its reference to the original website.

When any of the above happens you can immediately open a second tab and go to another website and there everything works normally, so this is not a connection problem (i.e. my internet connection is still working).

Other than this very frequent failure (on several different websites) I haven't seen many issues once the MacBook completes the boot process (which as I said earlier seems very slow in comparison to my previous OS -- that being Mac OS Sonoma). Yes, I skipped Sequoia since I had no real issues when running Sonoma, but I decided to update to Tahoe to try to fix a WebRTC issue I was having with Safari under Sonoma. Now, the WebRTC issues seem mostly resolved under Tahoe/Safari but with the new problems I outlined above. By the way, Google Chrome under Sonoma did not have the WebRTC problems I saw when running Safari and AFAIK Chrome is not showing these dead link issues either.
 
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