I had to replaced my old Rear Fan in my PC case. The new Rear Fan has 3-pins and the old one had 4-pins (PWM). The Rear Fan is plugged into the 4-pin rear header of my Intel DZ77RE-75K Mobo (with latest Bios 0066). The new Rear Fan is running however the Fan Speed is not reported anymore in the Intel Desktop Utilities (version v3.2.8.089). The speed old 4-pin Rear Fan was reported. It seems to me that the new Rear Fan is running at a constant speed and is not anymore controlled by the Intel DZ77RE-75K Mobo.
In the Intel DZ77RE-75K Mobo manual (March 2014 version), on page 12, there is a reference to "fan speed control using voltage control on Intel DZ77RE-75K Mobo (4-pin fan headers front, rear, and auxiliary) with selectable support in BIOS for 3-wire fans". I am assuming this would be a Voltage Modulation control of the new 3-pin Rear Fan speed based on the temperature detected by the Intel DZ77RE-75K Mobo. This is an option available on my old ASUS Mobo.
However, I could not find in the BIOS the option for selectable support for 3-wire fans.
Any suggestions?
Thank you.