I am interested in the B250M-HDV as mainboard for my new system.

The system is supposed become as quiet as possible with reasonable monetary effort.

I will equip an Intel G4560 CPU with a powerful heat sink with the intent to disable the CPU fan in light use of the PC.

My plan is to have a high quality 120 mm fan running at very low RPM in the rear of the case to provide the needed ventilation.

Moving on to my questions:

Most 4-pin PWM fans are noisier than 3-pin voltage controlled fans due to problems with commutation of the 12 V PWM signal, resulting in the fan bearings showing clattering sounds which become very noticeable at low speeds of the fan due to the reduced air flow.

To avoid those noises, my case fan of choice is 3-pin voltage controlled.

Obviously I don't want the fan to operate at maximum speed at a voltage of 12 V just like uncontrolled 3-pin fans plugged into a 4-pin header do, but instead at approximately 30 % of the maximum speed.

I searched the forums and found the following topic which is related to mine but covers relatively more expensive mainboards than the budget one I have in mind:

http://forum.asrock.com/forum_posts.asp%3FTID=2270&PN=1&title=asrock-bios-fan-control-is-it-equal-on-all-models" rel="nofollow - http://forum.asrock.com/forum_posts.asp%3FTID=2270&PN=1&title=asrock-bios-fan-control-is-it-equal-on-all-models

Since the specifications of B250M-HDV don't mention that its 4-pin headers offer Smart Fan Speed Control like the mainboard in the aforementioned thread, I would like to clear up some open questions before purchasing a mainboard that potentially does not offer what I need.