I installed Zorin on my 2015 macbook pro and I'm seeing very slow performance out the onboard GPU and my eGPU. My onboard GPU reads out as this when I do lspci:
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Venus XT [Radeon HD 8870M / R9 M270X/M370X] (rev 83)
My eGPU is an RX 5700XT running in a Razer Core enclosure. Performance on both cards is horrible, sub 30 fps in any title and even slow on the desktop when running through the eGPU. I thought AMD drivers were already in the Kernel am I missing something else?