I have a strange issue on my laptop which I strongly believe to be a software issue that I think should be repeatable on other Framework laptops with a 2256x1504 screen running Fedora 41 with KDE.
The screen works flawlessly while using 100%, 150% or 200% scaling, however when using 175% scaling nothing is rendered in the lowest two rows of the screen except the mouse cursor. That is the lowest 2256x2 pixels isn’t working correctly. They start out black so the issue isn’t very noticeable to begin with. But after use, and particularly resume from suspend, the area can get colored (typically white). It can start flickering which can be very annoying.
I discussed the issue with support. However they claim that the screen is broken and needs to be replaced. However since the screen is able to display whatever pixels I want when using different scaling I strongly doubt this. If anyone with a 2256x1504 screen and Fedora 41 with KDE could test this I would be happy to hear if the issue is visible or not.
At the moment I’ve only got a 2.8K display on hand, but I’ve encountered an issue similar to this before. In the past I owned a Thinkbook 13s that crammed a 2560x1600 display in its small footprint, so I can definitely understand the frustration. 200% scale is gives you an effective resolution of 1128x752 and 150% may leave screen elements feeling a bit too small to comfortably interact with.
Unfortunately I’m fairly certain that what you’re running into is an artifact of the scaling process. Generally speaking fractional scaling works by scaling up to 200% or 300% then scaling down from there. Even if the multiplication followed by division result in a whole integer, there are outlier cases where you’ll get artifacts such as a single line on your display being locked to a single color or similar.
If you don’t mind my asking, which mainboard is in this system? I’m curious if perhaps it may even come down to how Intel GPUs handle the scaling calculations as compared to AMD. I’m going to get my hands on a 2K display to test this out myself.
I have a Framework 13 with AMD 7840U. As far as I know there’s only one version of the motherboard for this model.
Certainly feels like it’s an artifact of the scaling process. I wouldn’t mind it that much if the lines remained black, but when it starts flickering it gets very distracting.
I understand. With the resolution of the standard 2K screen, 150% scale leaves things a bit difficult to read and 200% scale gives you effectively a 720p display.
On the old Thinkbook 13s I mentioned, it was running Ubuntu’s customized Gnome but what would happen is there would be a solid red line between the dock at the bottom of the display and any maximized application, and sometimes if there was another application near the bottom of the display it would instead turn into a single line static effect.
It may be worth experimenting with some other Desktop Environments or Window Managers to see if the issue manifests in the same way there, if you’re comfortable doing so.
Using Xorg instead of Wayland seems to resolve the issue (though it introduces some other annoyances due to the fractional scaling). Not sure what my preference would be. Maybe this is Wayland issue rather than a hardware one
I might have a similar issue: using 150% scaling with the 2256x1504 sceen on Debian/KDE5/Wayland, I will sometimes get a thin (~1px ?) vertical or horizontal line in the middle-ish of the screen that cannot be screenshotted, but I can ~reliably recreate in most programs.
What you’re both seeing tracks with my own experiences. Unfortunately this is likely a situation where you have to choose which type of artifacting you are willing to deal with. Wayland and Xorg are both going to have artifacts because ultimately fractional scaling relies on 2 steps for the final result. This is typically done with nearest neighbor or bilinear scaling in order to avoid introducing latency.
In theory there are now better ways to implement desktop scaling, such as using some form of AMD’s FSR or Intel’s XeSS, but there aren’t any implementations that I’m aware of yet. In the mean time, there is unfortunately no silver bullet solution for scaling artifacts produced by fractional scaling.
I am not sure I follow. I can buy that scaling can introduce some undesired artifacts. But in both our cases it feels like the artifacts are mostly bugs.
I would be happy with the line if it stayed black, but flickering I can not stand. I can not see how that behavior would be required for a scaling algorithm to work so I suspect it’s a bug. Maybe I should raise the issue upstream when I have time
Atleast the new 25.x have some issues but I am not sure if these have been fixed already.
I had some issues on our custom image (Fedora based Aurora atomic image) last week. But it seems KDE 6.3.2 (or possibly a mesa update) has fixed mine.
Although my issues were really minimal, had some small graphical clitches when using flatpaks (like zen browser) but these are now gone. My 2.8k screen is currently on 160% scaling in KDE.
Apologies if it seemed like I was trying to say that the flickering behavior was intentional or desired. My intention was to explain that the problem you’re seeing is a known issue with fractional scaling that is still being worked on. I would absolutely encourage you to open a bug report and help to create more pressure for a novel solution for these scaling artifacts.
