Ubuntu - GPU - OpenGL - Get the OpenGL Renderer

glxinfo | grep "OpenGL renderer"

returns:

OpenGL renderer string: AMD Radeon RX 5700 XT (NAVI10, DRM 3.38.0, 5.8.1-050801-generic, LLVM 10.0.1)

NOTE: If in the OpenGL renderer string: you only see llvmpipe, that means your system does not use the GPU but the CPU instead to render the computer graphics.