Here is another photo of display glitch happening when the computer hangs. I got it with both the Radeon X1950 and the Radeon HD 4670.
What happens it at startup, the GNOME Shell desktop makes an animation, expanding itself from the center of the screen. In such screenshot, we see the computer hang before the full size of the screen is reached (blues square is the frame of the screen). ** Attachment added: "Screen photo of GNOME Shell hanging on Linux 5.4.0-52 with ATI Radeon HD 4670 AGP" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1899304/+attachment/5429842/+files/20201027-215858-000.gnome-shell-hang-on-ati-radeon-hd4670-agp.jpg -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1899304 Title: Linux 5.4.0-48 (and later) causes GPU lockup, huge performance drop, makes GNOME desktop fail to start and games going from 70fps to 7fps, slow file loading, audio issues To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1899304/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs