After installing the operating system constant flicker. Ubuntu 18.10 & AMD RX 580. Screen artifacts - YouTube
You may be seeing this issue if you are using a Freesync monitor. Freesync is currently broken/not working with the current kernel (linux 4.18). This may change with a newer kernel (linux 5.0+), but for now you will have to disable it.
Update the file /etc/default/grub so GRUB_CMDLINE_LINUX_DEFAULT is set to
GRUB_CMDLINE_LINUX_DEFAULT="splash quiet amdgpu.dc=0"
On your next boot, you must set the refresh rate manually with the following command in the teminal:
$ xrandr -r 60
This will set your refresh rate to 60Hz. Other display modes can be shown by running xrandr with no options.
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