I currently installed El Capitan and it works well
but with OSX HIGHT SIERRA I have the problem with RADEON HD 6850.
but if I use nvidia video card it works
help please
I own 775 q9550 HD6850 for the system copying phase on SSD no problem. But when you start system installation procedure I can not perform, no video card is activated and remains black screen .You can help please.