why in linux there are 2 version - for rx and for nvidia... is it not possible to make unified version which works for both cards?
Then you would have drivers for both types of cards in the same machine. More overhead in my opinion. I did try the 580 and was not impressed as to what I got in return. They are power hungry and you have so many things to do to them to get the most.
The Nvidia side is just basic plug and play. With 2.0 its even better. But then each to his/her own there. Since I work 2 jobs, time is gold to me and have damn little of it right now.
As thaelin said they have 2 different drivers so watchdog and tempcontrol should use different scripts to check GPU utilization. temp control, overclock, voltage ,...
Also they have different miners too
So mixing all these in a rig will make the os much bigger and big time overhead in core system.