For me personally, blender uses ROCm and ROCm hiprt for Cycles tracing and cycles raytracing acceleration. I am using a Radeon RX 6800 and AMD Ryzen AI 7 350, and it works on Linux. ROCm HIPRT really does speed up cycles rendering (at the cost of more Vram usage). Of course, using the AMD driver on Linux, you get access to the system's RAM with GTT.