I share these tests because they could help others with the same problem. I am now certain that the problem is due to personal display profiles which somehow affect Illustrator. I tried several personal profiles (not recent ones) saving them both at user and system level (since having Filevault activated on my Mac this often causes problems) and the problem persisted with the latest Illustrator version. This morning I created a new profile with the i1Profile application version 3.7 (latest released) and installed it on Sonoma (14.0) and Monterey (12.7). In my case the problem disappeared completely on both machines, and now everything works. At this point I think it could really be a writing problem in the software that creates the profiles which somehow affects the correct functioning of Illustrator. In practice: Try to create a new profile with the latest available version of the profiling software, install it and restart Illustrator. It is not necessary to restart the computer since the problem, if present, appears immediately with every profile change after starting Illustrator.

This bug has been present for years now and it's absurd how it still hasn't been fixed. By now I have adapted and use templates with or without rulers depending on the use, but it is absolutely not normal in a performance sense. The problem occurs not only with rulers but also with the artboard tool in the same way. It's nice to have high-performance computers and not be able to use them with the software you use every day for work. I confirm that in my case too the bug disappears using standard system profiles. When I use my personal one created with the XRite tool (and that is always) the problem persists.

STILL a problem. MacOS Sonoma on M1 Mac mini. As a different user pointed out on a different bug listing it depends if a vanilla display profile provided by MacOS is used VS a color calibration profile for the screen that I created (I use display cal + I1 display pro).

So for default display profile activating rulers does not break GPU preview but for other profiles it does.

Same problem. MacOS Sonoma on M1 Mac mini. As a different user pointed out on a different bug listing it depends if a vanilla display profile provided by MacOS is used VS a color calibration profile for the screen that I created (I use display cal + I1 display pro).

So for default display profile activating rulers does not break GPU preview but for other profiles it does.

Same problem. MacOS Sonoma on M1 Mac mini. As a different user pointed out on a different bug listing it depends if a vanilla display profile provided by MacOS is used VS a color calibration profile for the screen that I created (I use display cal + I1 display pro).

So for default display profile activating rulers does not break GPU preview but for other profiles it does.

hola, Tengo el mismo problema NVIDIA GeForce RTX 3070 , cambia a vista de CPU y luego no puedo volverlo a GPU. tengo que cerrar el proyecto y volver a abrir para poder cambiarlo.

Especificaciones de la maquina.
AMD Ryzen 9 5900X
32GB RAM DDR4
WINDOW 10

We need more information about your machine and GPU.
I can’t reproduce this bug too, so it can be a machine-specific case.

I cannot reproduce this bug.
GPU preview works for me whether I have rulers visible or not, in all view modes - normal view, outline view and isolation mode. I can switch it on and off at will with Ctrl+e.

I even get GPU driver warning when starting Illustrator.

In Illustrator version 26.0.2 the GPU preview is disabled when rulers are shown or you enter outline or isolation mode. This bug has been around since at least v24.

How embarrassing....

For me, switching to the standard iMac color profile solved the problem. It seems like all profiles I installed with the calibration function in OS X as well as profiles created with X-rite meter and commercial calibrating applications break the GPU acceleration of Illustrator 2021 and 2022. The standard color profile for my iMac i9 (2019) as installed with the system (Big Sur) works flawless with Illustrator´s GPU display option.

I have a hardware calibrated monitor. This monitor was calibrated last time in Windows and the color profiles were copied from too. When I recalibrate my monitor on Mac this problem not makes slowdown.

If I use rulers the GPU preview switches back to CPU and the Illustrator slow down.
If I switch off the rulers and open again the GPU preview will OK.

Mac Mini 2020 M1
Illustrator 25.2.1 and 25.3 BETA

real-time GPU view does not work when rulers are active. The problem has existed since the first release of Illustrator 25 and has not yet been fixed. If I create a new document without rulers everything works, when I activate the rulers the view automatically switches to CPU mode I use illustrator on an iMac Pro with mojave 10.14.6.