The problem at hand is such an extreme corruption of graphics on the screen that the system is unusable. I have seen just about every other form of corrupted graphics, but nothing like this.
It started out as a “little glitch that came and went” and devolved into an extreme corruption of graphics that makes the system absolutely unusable because I can’t read any text, or see pretty much anything.
At first, it would manifest mostly when the screen was locked, sometimes when it wasn’t, and affect only the top 10-15% of the screen and a fixed-size square area down-and-right of the mouse cursor:
It was getting worse day after day, soon the entire screen was affected, the corruption looked like large areas of the image would turn one color (blue, magenta, green, etc.) following the content of the screen, see here how the corrupted areas align with the clouds, sky, water, etc. in the pictures:
At this point graphics are corrupted as soon as the login manager starts up, and as soon as I log in even the very simple splash screen is corrupted, and then the desktop is so badly corrupted I can barely see where the cursor is and I can’t really use the terminal. Even if I go to the text-only terminal with Ctrl+Alt+F2 the whole thing is so badly corrupted I can’t read anything.
Here is one photo and two videos: https://photos.app.goo.gl/RrjNDP8Tn7jhaH2S9
The photo and first video (Sept 14) show the lock screen, the second video (Sept 17) shows the login screen right after rebooting with the NVidia driver 515.
The card is an ASUS GeForce TUF RTX 3070 Ti O8G-GAMING (8 GB) purchased on June 2022 to replace an ASUS STRIX GTX1070 8GB purchased in August 2017. The new card had been working quite well until a few weeks ago, the problem started small but then started getting worse and I can’t seem to find a workaround.
When the problem started I was running Ubuntu Studio 20.04 with KDE Plasma. After a couple of weeks of trying a few tweaks (e.g. disable compositor) and seeing how nothing really helped, I decided to install Ubuntu Studio 22.04 and at first it looked perfect, but then the problem manifested again as soon as the first reboot with the NVidia driver.
At this point the latest NVidia driver on Ubuntu 22.04 is 515. Other versions available are 510 (2nd last) and 470. Tried going back to 470, thinking the problem started manifesting with a 5xx version, but the graphics are just as corrupted. The only workaround I have right now to be able to use this PC is to go back to the nouveau driver.
The same screen (Dell U3421WE 34" 3440x1440) and everything else works perfectly for long work shifts on a Lenovo laptop running Debian. Both computers share the screen via a StarTech 4k@60 DisplayPort KVM switch (and all cables are DP 1.2 rated 4K@60), I am able to switch from an extremely corrupted display on the PC to a perfectly fine display on the laptop, back and forth just fine. Tried connecting the screen directly to the GPU with a brand new DisplayPort cable but, unsurprisingly, it didn’t make any difference.
So far the problem seems to be in either the GPU (hardware) or the NVidia driver (515) but I’m hoping this is just something gone bad in the system environment that somehow triggers a problem that only reproduces with the above combination. Attaching logs from nvidia-bug-report.sh run after logging in with the corrupted graphics (collected via SSH).