witcher 3 and windows 10 has some issues , mine personally crashes after a little while of playing , for witcher 3 simply override tessellation to x 16 " ccc profile for the game" and it should play just fine
I have the Problem already with Witcher 2. havent bought Witcher 3 yet
Using Windows 7 pro 64x on my System made Witcher 2 run >+8 fps.
sorry I meant witcher 2 crashed, my fps was well above 60 though and seem to not really be cpu bound at all I also run fx
I have similar problem as you . No mether what setting I put , my fps is 27 at first mission . Gpu and Cpu usage are vary low at 15 % on lowest and no more then 50 on ultra setting (no Uber-Sampling) for Gpu , and for Cpu usage stays at 50 %. .
Changing from ultra to low give me no more fps .
In some missions later on my Gpu usage rise to 99% when I get 70-90 fps.
Phenom 2 x4 overclocked to 3.6 ghz
Ati readon R9 270x vaporx 2gb gddr5
4 gb ram .
Drivers are up to date .