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Answered

Photoshop on Mac OS 26 are causing extremely high GPU usage from the WindowServer process

Forum|Forum|3 months ago
April 19, 2026
13 replies
721 views

I have several M1 Macs—from Mac mini to iMac—and they all have the same issue. Whenever I open Photoshop, Illustrator, or InDesign, even if I don’t do anything, WindowServer will jump to around 80–90% GPU usage. Once I start working with files, even just opening a single image, the whole system becomes choppy and starts dropping frames, with GPU usage almost maxed out.

But : if I switch the app to full-screen with menu bar mode (press F), the window shadows disappear, GPU usage drops back to normal, and everything runs smoothly—even with large files open. This makes it pretty clear the issue is related to how window shadows are being handled in macOS 26 and how it interacts with Adobe apps.

It’s been months since Adobe 26 came out, and I’ve been waiting for updates to fix this, but even the latest versions still haven’t solved it. At this point, I’m wondering if it’s even fixable.

M1 Macs are not that old—most Mac minis and iMacs from around 2021–2022 are still M1, so they’re definitely not outdated. It shouldn’t be the case that running basic Photoshop functions causes this level of lag. Mac and Adobe are supposed to be a perfect combination.

Even though macOS 26 seems to put more load on the GPU, Apple’s own apps don’t have this issue at all. For example, Final Cut Pro runs large projects smoothly without any problems like this caused by window shadows.

I really hope this gets fixed. Or is it just impossible to solve, meaning the only options are either upgrading to the newest Mac or back to macOS Sequoia?...

Correct answer elgasa

Although this isn’t a fundamental solution, I’ve found a workaround other than ‘Full-screen mode with menu’, so I’m reporting it here.

This workaround can be applied to all the affected applications—Photoshop, Illustrator, InDesign and Dreamweaver. Even if you have all four running simultaneously, the GPU usage will drop to 0% if you leave them idle.

[How to do it]

Go to Menu > Window > and deselect ‘Application Frame’.

After that, arrange the panels as you wish and save your workspace.

Z

zrngajic

Participant

Same issue confirmed on Intel — with measurements and a documented root cause + one-line fix from Chromium's source code.

Setup: iMac 27" 2020 (Intel), AMD Radeon Pro 5500 XT 8 GB, 64 GB RAM, macOS 26.5.2, latest Photoshop 2026 and Illustrator 2026.

Symptoms — identical to OP: with Photoshop and Illustrator open in windowed mode, WindowServer climbs continuously (I measured it at 83% CPU / 28% GPU in Activity Monitor, with GPU History pinned near max). The entire system stutters — cursor, window switching, everything — not just the Adobe apps. Quitting one of the apps (or Photoshop crashing) instantly frees the GPU and the system recovers. RAM is irrelevant: 64 GB installed, memory pressure green, swap at zero while the problem is active.

I can also confirm the workaround: pressing F (Full Screen Mode with Menu Bar) makes the problem disappear immediately — GPU History drops to normal in real time. Since fullscreen windows have no shadow, this points at window shadow compositing, exactly as OP suggested.

Important: this thread's reports are all Apple Silicon (M1/M3). My machine is Intel/AMD — so this is NOT an Apple Silicon–specific issue. It affects the whole macOS 26 + Adobe combination regardless of GPU architecture.

Now the root cause, documented in Chromium's source code. See components/remote_cocoa/app_shim/native_widget_mac_nswindow.mm (function AreWindowShadowsDisabled, around line 31):
https://source.chromium.org/chromium/chromium/src/+/main:components/remote_cocoa/app_shim/native_widget_mac_nswindow.mm;l=31

Google's engineers document that when window-server-generated shadows are combined with layered windows and heavy compositing load, WindowServer becomes unstable — in their words, it seems to crash "with distressing frequency" (their bug trackers: crbug.com/899286, crbug.com/828031, crbug.com/515627). Their mitigation is literally one line: overriding setHasShadow: to force NO on affected windows.

Adobe app windows are exactly this case: very large, layered, shadowed windows — and macOS 26 clearly made the shadow compositing path much more expensive. Users cannot patch this from outside (SIP / hardened runtime prevents it), so it has to come from Adobe: either call setHasShadow:NO on the main application window on macOS 26, or add a preference to disable the window shadow, until Apple fixes the regression on their side.

This is a one-line class of fix for a bug that currently makes Photoshop + Illustrator barely usable outside fullscreen. Please escalate — happy to provide any additional measurements or logs.

mig90501573

Participating Frequently

I can confirm that this solved it, now the GPU utilization, so far, does not go off the rails!

E

elgasaCorrect answer

Inspiring

Although this isn’t a fundamental solution, I’ve found a workaround other than ‘Full-screen mode with menu’, so I’m reporting it here.

This workaround can be applied to all the affected applications—Photoshop, Illustrator, InDesign and Dreamweaver. Even if you have all four running simultaneously, the GPU usage will drop to 0% if you leave them idle.

[How to do it]

Go to Menu > Window > and deselect ‘Application Frame’.

After that, arrange the panels as you wish and save your workspace.

S

sputnik6

Known Participant

THAT WORKS, THANKS A TON!!

tomzag

Inspiring

Just wanted to flag that I'm hitting the same bug. I've written up a detailed report on the Photoshop Prerelease Forum, and Adobe has now logged it.

My Photoshop Plugins: plugins.pixelsucht.net

S

sputnik6

Known Participant

I have the same problem and had opened up my own thread before finding yours. Will follow.

Ged_Traynor

Community Expert

@Gleeful_videography15B9 there’s a similar reported issue here

G

Gleeful_videography15B9

Participant

Hey everyone,

I've been trying to figure out what's wrong with Illustrator and Photoshop for the past months. But the situation is getting unbearable.

I have a MacBook Pro M1 Max and a MacBook Air M4. Both with the same macOS Tahoe version, and the latest Adobe Photoshop and Illustrator versions.

When both are sitting completely idle with nothing open, they're at 0% CPU and 0% GPU load.
Then I open Illustrator. No document. I don't touch anything. Just the app sitting there. I check Activity Monitor and the WindowServer process shows:

on the M1 Max, 0% GPU
on the M4 Air, 20% GPU

The situation gets worse when I open Photoshop at the same time, where
the GPU goes to 50% load for the M4 Air just by doing nothing.
The M1 Max stays at 0%.

Of course when you do actual work in the programs, the GPU load gets even higher, to a point where they get laggy and unbearable to work with. The M1 Max shows no such problem.

I tried the following and nothing worked:

Turning off Animated Zoom
Turning off Real-Time Drawing and Editing
Closing the Libraries panel and the Discover panel
Resetting prefs with Cmd+Option+Shift on launch
A full reinstall of Illustrator and Photoshop
A clean macOS install on the M4 (yes, really)

The only thing that works and brings the GPU back to 0% is putting Illustrator and Photoshop into full screen (by pressing F).

My guess is that Tahoe and Adobe aren't optimized yet for the M4 🤷‍♂️.

Please fix it Adobe.

Sameer K

Community Manager

Hey, all. Thanks for bringing this up. I’ll help you figure this out. On macOS, all GPU compositing routes through WindowServer, making Photoshop's draw calls visible in the Activity Monitor.

In Photoshop’s settings, go to Performance > Uncheck ‘Foreground Composite Caching’ & go to Advanced Settings > Uncheck GPU Compositing and restart Photoshop.

Let me know how it goes. Thanks!
Sameer K

E

elgasa

Inspiring

What you are referring to is the internal processing within Photoshop, Illustrator and InDesign. There is no change in GPU usage (the attached image shows Illustrator and Photoshop running with settings that do not utilise the GPU). As GPU usage varies depending on the display mode, this is unrelated to the applications’ internal rendering engines. This difference is likely due to whether or not window shadows are applied to the overall interface.

mig90501573

Participating Frequently

I have the same problem on a mac studio m1 max, the GPU starts climbing up to like 85% gpu utilization and the whole system is a stuttering fest. Adobe please fix this, so far updates have not solved the problem

shustovcreates

Participant

I have the same exact issue on my 16 inch MBP M1 Pro. it makes laptop super hot all the time and battery dies 2-3 times as quickly

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