The triumvirate of OSes that can run on the X5000 (OS4.1FE, MorphOS, linux) still lack a fully featured common GPU implementation.
And will lack in the future.
Is theoretically possible, that MorphOS and AmigaOs will have support for the same more modern cards, but I think linux will never have it.
There is a bug in amdgpu PPC big-endian version, and new improvements focuses on little-endian.
But who knows, maybe I'm wrong and someone will be dealing with decades old things from which he has no profit, except joy
AmigaOS: Pegasos II, Sam440ep-flex, Micro A1-C, AmigaOneX1000
MorphOS: Pegasos II, Powerbook G4, iMac G5, Powermac G5 Quad