I use the Plasma desktop environment on a Gentoo Linux system. Yesterday I upgraded Plasma 5.14.5 to version 5.15.0. Now SDDM (with the Breeze theme) is very slow at login, especially when you need to type the password. I really think the problem is due to commit dbb19ba333043670b616bfa586b054685892f531 because I successfully tried installing plasma-workspace-5.15.0 and then manually replacing /usr/share/sddm/themes/breeze/components/{Clock.qml,UserDelegate.qml} with those from plasma-workspace-5.14.5.1. I have a 10-year old Intel Core 2 Duo desktop computer with an integrated Intel GPU.
Have you manually set software rendering somewhere? If not I don't see how it could have caused it
I haven't explicitely set software rendering anywhere. But on my system I only have the following option: # eselect opengl list Available OpenGL implementations: [1] xorg-x11 *
Also: # glxinfo | grep "direct rendering" direct rendering: Yes
Oh, wait. I just found the "Plasma Renderer" module. Option "Rendering Backend" is currently set to "Software". The other possible option is "Open GL". I'll do some testing tomorrow.
>Option "Rendering Backend" is currently set to "Software". The other possible option is "Open GL". That's mostly what I expected to hear, except you said "login screen" where (due to another more complex bug) that setting doesn't apply Could you mean the lock screen?
I just did some testing. Unfortunately even if I set "Rendering Backend" to "Open GL" both the login screen and the lock screen are still very slow. I guess there's something wrong with hardware acceleration on my system...
I'm not sure if related, but I also have another similar problem. Certain online videos (but not all) on Falkon are played in a terribly slow way on my system.
I asked for help on the Gentoo Forums: https://forums.gentoo.org/viewtopic-p-8311486.html
Looks like your chipset only supports OpenGL 1.4. I am pretty sure Plasma 5 requires at least OpenGL 2.0, which is already 15 years old.
I ordered a used Intel motherboard with a more up-to-date Q45 chipset supporting OpenGL 2.0. In this way I will also be able to switch from xf86-video-intel to the modesetting driver. I really hope this will fix my problems.
Today I installed the new motherboard (Intel DQ45CB). It now supports OpenGL 2.1. The problem with lock screen and the login screen is gone. Thank you!