I sold mine (model 56) because there was too much strange noise regardless of the speed of the fan. I had every movement of windows or video, flash animation, any movement in the picture was accompanied by a strange noise like a mechanical hard drive. and the worst is that I tried with 2 identical graphics cards from Sapphire Brand. impossible to determine where it could have come from ?! one thing sure, all works perfectly on windows 10. silent and especially without scratching noise. I have a big PC that I use like Slave (For VIENNA ENSEMBLE PRO software) and I have only one screen to manage the Hackintosh then the PC, I use Microsoft Remote desktop that allows me to switch from one screen to another with the same keyboard and mouse. Well, figure it out again, when I'm on the windows window, no more noise, nothing, silence. and when I switch with Mission control (using CTRL + ->). Hop the strange noise come back. a nightmare. I dropped and sold it today.
I do not know what to buy back ..
I hope my experience will help someone.
Ps: i tested with 2 windows 10 on differents machine and Sierra too. tested different kexts, clover settings, bios etc..
I don't speak about speed fan, the kext VEGAtab works wonderfuly for that. it'is only about scratch and strange noises.