Hello everyone, I've got some serious lag in using graphical applications since Sunday. I was able to narrow it down quite a bit, but I can't find a solution. I'm using a ThinkPad P50s with Intel HD 520 and NVIDIA Quadro M500M graphics (but, AFAIK, only the Intel Graphics are used) with X11 and i3. Since Sunday, when using applications like thunar, xfce-terminal, firefox, thunderbird, ... every interaction (starting, clicking a menu, a menu item, sometimes even hovering) caused the whole GUI to freeze from ~5 secs to up to 30 secs (thunar seemed to be the worst, with folders opening in no less than 30 secs). However, scrolling lists, webpages, typing text, using terminal applications... worked with no lag. I ran multiple system updates every day, ensuring that my system was up-to-date, nothing helped. I tried switching to KDE then, noticing that while the old applications still caused the same lag, all KDE-Applications (KDE file manager etc.) worked with no lag. When switching from X11 to Wayland with KDE (or replacing i3 with sway), even the old applications (thunar, xfce-terminal, firefox, thunderbird, ...) work with nearly no lag. However, sometimes GUI interactions in thunderbird or firefox still cause high lag. When using XFCE, though, I couldn't find any noticeable lag. I tried downgrading the following packages (in that order): * mesa-vdpau (19.1.6-2 -> 19.1.5-1), lib32-mesa (19.1.6-1 -> 19.1.5-1), libva-mesa-driver (19.1.6-2 -> 19.1.5-1) * gtk3 (1:3.24.11-1 -> 1:3.24.10-1) * qt5-base (5.13.1-2 -> 5.13.0-7), qt5-declarative (5.13.1-1 -> 5.13.0-1), qt5-graphicaleffects (5.13.1-1 -> 5.13.0-1), qt5-imageformats (5.13.1-1 -> 5.13.0-1), qt5-location (5.13.1-1 -> 5.13.0-1), qt5-multimedia (5.13.1-1 -> 5.13.0-1), qt5-quickcontrols2 (5.13.1-1 -> 5.13.0-1), qt5-quickcontrols (5.13.1-1 -> 5.13.0-1), qt5-script (5.13.1-1 -> 5.13.0-1), qt5-sensors (5.13.1-1 -> 5.13.0-1), qt5-speech (5.13.1-1 -> 5.13.0-1), qt5-svg (5.13.1-1 -> 5.13.0-1), qt5-tools (5.13.1-1 -> 5.13.0-1), qt5-webchannel (5.13.1-1 -> 5.13.0-1), qt5-webengine (5.13.1-2 -> 5.13.0-1), qt5-webkit (5.212.0alpha3-4 -> 5.212.0alpha3-3), qt5-x11extras (5.13.1-1 -> 5.13.0-1), qt5-xmlpatterns (5.13.1-1 -> 5.13.0-1) * nvidia-utils (435.21-1 -> 430.40-2), nvidia (435.21-4 -> 430.40-5) * linux-headers (5.2.14.arch2-1 -> 5.2.4.arch1-1), linux-hardened-headers (5.2.14.a-1 -> 5.2.8.a-1), linux-firmware (20190815.07b925b-1 -> 20190717.bf13a71-1), linux-hardened (5.2.14.a-1 -> 5.2.8.a-1), linux (5.2.14.arch2-1 -> 5.2.4.arch1-1) * linux-firmware (20190717.bf13a71-1 -> 20190628.70e4394-1), linux (5.2.4.arch1-1 -> 5.1.16.arch1-1), linux-hardened (5.2.8.a-1 -> 5.1.16.a-1), linux-hardened-headers (5.2.8.a-1 -> 5.1.16.a-1), linux-headers (5.2.4.arch1-1 -> 5.1.16.arch1-1) * mesa (19.1.6-2 -> 19.1.5-1) And did a reboot after each step. However, none of them changed anything. Any ideas? Why does switching from i3 to KDE or even XFCE resolve the issue (partially)? Why does switching from X11 to Wayland do so as well? I'd like to continue using i3 without lag. Thanks in advance, Lukas