update: First test shows that lowering memory speed and getting back to very old crimson beta driver helps for now, at the cost of 3-5% lower performance. Memory usage around 3,895 MB
HWinfo shows that old driver is using around 27-29 MB of dynamic D3D memory while new driver is using more then 130 MB, at least for me.
Can you please tell me which version of old Crimson beta driver are you using now? Will 17.11.4 do?
I too face 0MH/s with my RX570/470 4G since today on Windows 10, Adrenaline driver v19.20. Only monitor is connected to integrated mobo graphics (HDMI port), yet Windows still not allowing to allocate more than 3737 MB of VRAM (according to HWInfo). -eres 1 or 0 doesn't help, lowering GPUs' memory timings to 1700 (instead of ~2000) gives no change.