You may want to check if you have one of the app listed here[1] on your system.

Electron based apps cause a huge system wide lag on macOS 26 due to the use of a private macOS API[2]. This bug has been fixed in Electron but not all Electron-based apps have been updated yet.

[1] - https://avarayr.github.io/shamelectron/

[2] - https://github.com/electron/electron/issues/48311

I don't think that's the UI, it's some other bug. My M1 is still running at full speed after Tahoe. Some people have said there is a broken version of Electron which causes slowdowns on Tahoe currently, most but not all apps have updated to a newer fixed version of Electron.

The M3 can run modern 3D games at high frame rates, surely it was something else about the update than the glass effect in the UI causing slowness??

It's a more appreciable burden on older iPhones though.

The glass transparency effect is just very computationally expensive.

The glass UI renders on my Apple Watch 6 just fine and that thing has probably 0.5% the GPU power as the Macbooks.

There's visible lag & stutters opening the control center on my Series 10.

Likewise, while it performs "fine," interacting with the UI still feels sluggish on Tahoe on my M4 Pro compared to Sequoia. I still have another M4 Pro with sequoia on it and it's a night and day difference, in favor of Sequoia.

There may not be any real performance loss but there is definitely UI latency and it's very noticable.

Like others have said, check whether you have any Electron apps that weren’t updated with the latest Electron framework. Both my M1 Pro and my work M3 Pro don’t feel any slower (unless I open an offending Electron app). I was updating a Mac that uses Sequoia yesterday and it didn’t feel any faster.

Your watch also has a screen resolution of (3024 * 1964) / (368 * 448) = 36 times less than a Macbook, so it's all a wash. Except the wasted coulombs.

It also renders on my M1 Macbook just fine as well for what it's worth. If it's running slow, it's because something is bugged out rather than the UI inherently being too heavy.

I just don't understand how if Visa could render its transparency efects smoothly on Intel 920 grade GPUs with 128mb of ram.

That's not how I remember it. Back in the day the first thing you did was disable the Aero stuff to claw back some performance on Vista.

That said, who knows how efficient the implementation is compared to other changes in iOS 26. I turned liquid glass off with "reduced transparency" because even 1% extra battery usage for it would be too much even though I kinda appreciated the new look.

>>That's not how I remember it. Back in the day the first thing you did was disable the Aero stuff to claw back some performance on Vista.

I remember it being kinda like placebo - you did, you marvelled at how much faster it's working, but in reality nothing changed. I really liked the look, and it did run smooth unless you had something below the minimum spec(which a lot of people did at the time).

I mostly disliked Vista for a number of reasons, but the looks were incredible. I was actually blown away at the beauty

I liked aero too, XP was too fisher price.

XP Media Center Edition had a pretty slick theme, not at all toy-like. To say nothing of the Metro interface in its titular app, though it seems Metro was kind of a dud when they tried to apply it to other apps.

Vista problems were largely nvidia driver crashes and low spec machines. Otherwise vista was fine.

Yes, though I think it worth noting that at that point "low spec machines" was like 80% of laptops and maybe 50% of desktops. It also really hurt when you went from XP which ran great to Vista which noticeably dragged on your machine.

My friend had an Alienware laptop which absolutely screamed with Vista

Vista did translucency and a statically positioned reflection mask, whereas this glass effect involves refraction/tinting that samples from surrounding surfaces.

It barely handles that, and even the M5 still cannot cope with 8khz mouse input coupled to a high refresh rate (>240) screen. I laugh every time they try and sell us on these things being able to play games

Even looking at pro CS players, a single 8 KHz entry is found in the table at https://liquipedia.net/counterstrike/List_of_player_mouse_se..., so it's a really odd hill to try to die on.

They really are great gaming machines from a hardware perspective. I wouldn't bother with an x86 laptop for gaming if it weren't for the software (mostly DRM) side.

That is wildly outdated, everyone is using 8khz input now. Keyboards too. This also completely ignores the 600-640hz monitors they are playing on.

Even 1khz mkb input on an apple silicon mac connected to a 500hz screen has insane utilization just doing shit in the OS. They are also struggling with variable refresh rate, improperly dropping down to the minimum (as low as 24hz) with jarring, jagged jumps up to the maximum after a few seconds of use.

This is a solved problem on both windows and linux. Even Asahi does a better job.

No, not "everyone" is using 8 KHz polling now... it breaks a lot of game engines for no benefit (even 4 KHz) but is heavily marketed because higher numbers. Worse yet, 8 KHz eats the kernel with interrupts (even on my 9800X3D) instead of letting the game run as fast as possible.

High refresh rate monitors are great, yes, but those are still sub KHz - you're talking about polling a mouse at 13x the rate of the highest end esports monitors as some minimum bar for when a machine can be for gaming - get out of here with that kind of artificial gatekeeping.

No complaints about Asahi though :).

Not "everyone". The G Pro Wireless is one of the most popular mouses and polls at 1KHz, and it works just fine. Polling a keyboard beyond 1KHz is utterly useless. The only time you're gonna want more fidelity is with stuff like Snap Tap, which is considered cheating and is banned.

In a similar vein, >120Hz screens are of doubtful utility. The performance gain is insignificant, considering top human reaction time to visual stimuli is ~150ms and the jump from 120Hz to 240Hz is -4.17ms, 1/36th or 2.77% improvement.

Even then, most pro FPS players also still play on 200-800 DPI when 1600 DPI and preferably even 3200 DPI is much better. Those low DPIs are purely cargo culted from the 2000s era CS Pros their .cfg, when sensors were still pretty crappy, and those players are effectively running lowgrade mouse smoothing.

Uneducated gamers are kin to uneducated audiophiles. Stop drinking the snake oil.

?? isn't it objectively the fastest ST core out there, topping MT benchmarks as well? Depending on the variant the M4 plays cyberpunk at 50-120fps so what are you saying?

The problem is the edge cases where people use hardware capable of absolutely ridiculous things that nonetheless are common-ish on Windows and expect macOS to be capable of dealing with as well.

(Don't get me started on macOS and the un-disableable mouse acceleration override coupled together with Steam Link...)

LinearMouse is a bandaid for the latter problem.

Benchmarks are one thing. Real world usage and I/O are another.

There is no world where 50fps is acceptable in any game in 2025. Flagship GPUs on high end systems running Windows manage 4k @ max settings north of 60, nearly double that with RT off. To achieve anything close on a mac, you're dropping down to 1440p, at lower settings, with frame generation.

Lol ok buddy you’re not accounting for the 50W vs 500W difference. Gotta compare to windows laptops on battery.

They’re about the level of a 4060 https://m.youtube.com/watch?v=LWfM7Ktsal0

Wasn't Windows 7 doing this same stuff back in like 2009?

If we follow the same pattern, iOS 27 and corresponding releases will be completely flat and look like Mac OS System 7. Chicago font wants to live another day.

Windows 8 got some serious hate back in the day, it had some sound ideas that were implemented poorly, but no one could deny it was lightweight. It had the smallest memory footprint of all the modern Windowses IIRC.

Unironically Mac OS 7/8/9 felt the best IMHO. Even though there were some missteps (the https://en.wikipedia.org/wiki/Control_Strip was awful) and 9.x got a bit overloaded towards the end.

Mac OS X (and macOS still) never felt as good.

Apple's classic human interface guidelines were well thought out. They should consider rereading them sometime.

Tiger was fine :D

Tiger still had that weird thing where half the apps were brushed metal for no apparent reason.

A lot of people argue it peaked with snow leopard; that was consistent, performant, and feature complete, not yet overly influenced by mobile.

Nah liquid glass isn't just transparency and gaussion blur, it refracts/bends light around the rims as well as a kind of sub pixel colour splitting on some elements like when you have a water droplet magnifying your screen.

That sounds like maybe a few more multiplies and applying slightly different constants to different colour channels. There is no complex simulation happening.

Sounds like some computationally expensive, unnecessary bullshit.

Even an iGPU from a decade ago could handle that easily. There is some other problem with the new UI’s performance.

I think the liquid glass transparency is more complex than Aero - with curved glass objects distorting what's behind them significantly in some cases. Don't know how much more computationally intensive that is.

I think LG made the finder windows buggy as they have issues focusing when I click on them. Didn't have this issue before Tahoe

I have an M3 max and see literally no difference in performance. YMMV I guess!

I do have performance issues on my iPhone 13 mini, but I expected it.

I migrated from a 13 Mini to a 17 Pro last week. Updated the Mini to 26 beforehand to mitigate any potential 18->26 issues with data transfers/backups.

I'm still getting accustomed to the device size, the Mini was such a perfect device. If only app and web developers would actually preview their work on its dimensions, I probably would have just replaced the battery (76%).

Reduced Transparency is a hard requirement for iOS 26.

I just replaced the battery on my 13 mini (actually I got a brand new one since I still have Apple Care+ on mine and I did an express replacement). I’m good for an other 2 years.

Yeah, I'm keeping mine around and not trading it in. I might get the battery replaced at some point anyways and continue using it as a secondary device for some workloads.

Missing my Mini too

I mean your M3 Max has a 3-5x bigger GPU than OPs base M3, you'd certainly hope it could rip through those new shaders.

The shaders are nothing. I’m kind of appalled by everybody telling “oh shaders, it’s expensive!”

OP probably has been hit by the electron bug, which does indeed kill the performance of the whole OS…

I haven’t noticed any performance issues on my M3 Air, other than the Ghostty / Zed scrolling lag issues that were fixed in a software update.

Four trillion