GNU/Linux Ubuntu 18.04 Installing AMD Open Source Drivers Guide
How to Install AMD Open Source Graphics Drivers in Ubuntu 18.04 Bionic LTS GNU/Linux – Step by step Tutorial.
And Open Source AMDGPU Graphics Drivers for Ubuntu Bionic includes Updated Free Graphics Drivers for AMD/ATI Graphics Cards.
These drivers are based on the Mesa 3D stack and support modern AMD GPUs using the AMDGPU kernel module.
Especially relevant: as a complement you may be intesested also to the MESA Graphics Drivers Suite Setup.
Moreover, this Open Source AMD Graphics Ubuntu PPA is automatically Updated on Every Upstream Change.
Most noteworthy: this Driver may require a Kernel Upgrade as prerequisite so you may see instead How to Install Amdgpu Pro on Ubuntu 18.04.

1. Launching Shell Emulator
Open a Terminal window
Ctrl+Alt+t on desktop
(Press “Enter” to Execute Commands).
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