No, no, I didn't set anything special in DaVinci. I just tried the difference between manual and automatic selection of Graphic card, but the result seems to be the same = no success = very poor encoding performance to H.265 ... see image below
View attachment 5034
Unfortunately there is no possibility to encode via UHD630 (even that iGPU is listed), because it is not selectable and is grayed-out as you can see. This would be a sufficient workaround for me, because encoding via iGPU was quite fast.
BTW it is a free version of Davinci.
Thanks for any help.