I have a constant struggle with Illustrator for the last year or so. Every time I work in a document, no matter the size, the elements I have in it, colour space and so on it keeps switching from GPU to CPU preview. After that automatic switch, the performance drops significantly, and it's almost impossible to work in it.
I've uninstalled Illustrator, removed all presets, uninstalled the complete Creative Cloud and can't seem to find a solution on why it's happening. Every other software (Blender, performance-heavy games, etc.) is running perfectly smooth. It's just Illustrator and sometimes Photoshop that's giving me a headache.
I did find a quick hack to solve my problem. If the GPU preview gets deactivated, I have to go to Window -> New Window to create a new window for my current document. After that, I can work for sometimes a couple of minutes, sometimes just for one action before it gets deactivated again and I need to restart that game Illu wants to play with me.
It got to that point that I am seriously considering cancelling my CC subscription and get any other vector software because it's that damn annoying. Hopefully, someone had the same problem, or you guys can help me.
Ryzen 7 1700X
ASUS CROSSHAIR VI HERO (Bios Version 7704)
Gainward GeForce GTX 1080 GLH
Windows 10 Pro - 64 bit
And what kind of documents are you working on? Do you use color management? Is the graphics driver up to date? There's more to this...
Drivers are all up to date, from mainboard component drivers to graphic card, etc.
Documents I work on vary, from illustrations for tees, flyers to logos or typographic artworks. But like I said it can be an empty document and I just write in Arial a single character and it switches back to CPU Preview. I've also deleted every manually installed font and removed all adobe fonts. This is a solitary problem in Illustrator and Photoshop, InDesign, After Effects or Premiere Pro for example run fine.
It happens both in RGB and CMYK Color Mode. Working spaces have been altered between Monitor sRGB, Adobe RGB, SWOP v2, ISO coated v2 300%, Euroscale Coated and uncoated. It doesn't matter, it keeps deactivating GPU Preview.
I've also tried multiple ram tests, checked my hard drives for errors, hooked up another monitor (running 2x Dell U2515H). The only thing I haven't swapped yet is my CPU, but as I mentioned I can run hardware hungry games on this machine without any problem. I recently played Cyberpunk and had some minor bugs at a 2560x1440 resolution with ultra settings in-game. So I doubt that it is a performance issue, there must be something that is messing with these two programs.
Sorry to hear about your experience. Please update Adobe Illustrator to the latest version(25.2) & let us know if you still have such concerns. You may follow this help article to know how to update the app.
Looking forward to your response.
Well, it seems that for now, it solved my problem. I played around with some older files and Illustrator didn't switch to a CPU Render Preview, yet. I'll keep you posted when I work with it a bit longer, but it seems that your latest update did the trick.