In PWM mode the fan is fed 12v constantly, and then a PWM signal is sent up the fourth pin to the fan to control it. PWM control is also used in your VRM and throughout your motherboard in many different places.

If you feed a fan 12v constant and use a 50% duty cycle PWM rate, then you would theoretically get 6V. That would result in a 50% duty cycle since you are pulsing (turning on) half the time. So let's say in a 10-second cycle we pulse five times to 100% for one second each time. These pulses result in a duty cycle, which can be used to calculate final voltage. Software-wise, the ASRock Z690 Pro RS is compatible with 64-bit Windows 10 and Windows 11 versions.PWM Mode (4-pin fans): Stands for pulse width modulation, and it basically means you get pulses (basically going to an ON position) at a periodic rate, and in this case, it's thousands of times a second.

The motherboard comes alongside a printed guide, support CD, I/O Shield, as well as a graphics card holder, one standoff for M.2 socket, four screws for M.2 sockets, and a pair of SATA data cables. For those who are planning to use this board in a liquid-cooled setup, there are a total of five pump fan connectors with smart fan speed control. A trio of addressable LED headers is also present, accompanied bu one RGB LED header. The highlights of the ASRock Z690 Pro RS ATX LGA 1700 motherboard include a 13-phase Dr.MOS power design, 8 X SATA3, 2 X USB 3.2 Gen2, 6 X USB 3.2 Gen1, a single USB 3.2 Gen2x2 Type-C, Dragon 2.5G LAN, Realtek ALC897 7.1 audio, PCIe 5.0 x16, as well as support for DDR4 5000 MHz overclock. The aforementioned source reveals that this value was reached on Octoas well. However, this is not the first time this motherboard drops to US$158.99. Now, a 26% discount pushes this piece of hardware to what appears to be its lowest price ever ( according to Camelcamelcamel). With a list price of US$249.99, the ASRock Z690 Pro RS motherboard is a reasonably-priced LGA 1700 motherboard for both 12th Gen and 13th Gen Intel Core processors, as long as the user is willing to settle for DDR4 memory.

Asrock motherboard fan control