Most linux desktops work fine on ARM chips FYI. GPUs in the ARM world are usually just for OpenGL used by video games. Video decoding/encoding is handled by a

Most linux desktops work fine on ARM chips FYI. GPUs in the ARM world are usually just for OpenGL used by video games. Video decoding/encoding is handled by a VPU (not GPU), HDMI is handled by a separate HDMI PHY, and most of these components have mainline, libre kernel support if you use an Allwinner based single board computer. Microsoft has started branding some Mali GPUs as DirectX 11 capable, though YMMV on using these features.