Power Consumption

We measure CPU power consumption since one of our first tasks is to truly verify system stability. I isolate the power coming through the 8-pin ATX connector using an in-line meter that provides voltage and current readings, and total wattage passed through. While this may not prove to isolate the CPU power draw in all instances, it does serve as a good indicator of board efficiency and effective VRM design. Total system power consumption is no longer reported as this figure can change depending on what VGA is installed. The sole board-only power measurements possible without physically modifying a motherboard are those taken via the 8-pin CPU connector, making it the only figure of value worth reporting. I use wPrime with eight threads selected in its options since it provides a consistently high workload throughout the full length of the test and runs long enough for the VRM and CPU to produce a fair bit of heat. Most average workloads will draw far less than that, although distributed computing applications are quite similar. This is not supposed to test stability since I use several other applications to do so, but merely serves to provide repeatable power draw numbers anyone can replicate. The meter used is an off-the-shelf Zalman unit that has been on the market for some time. In my test environment, it provides results similar to a FLUKE 337 clamp meter.

Fan Control

*Fan speed is controlled by temperature, with set on and off points controlled via the PWM function.


Fan control on the ASRock Z170M OC Formula is fairly good, with five 4-pin headers available for you to plug your fans into. Inside the Z170M OC Formula's BIOS are options to adjust the profile the fans use, with ASRock's "Fan-Tastic Tuning" utility offering an easy-to-use graphical interface for setting manual fan curves or picking pre-determined profiles.


You can have the fans shut off completely with a temperature-controlled range of 30 °C to 80 °C offered both through the graphical interface and via "standard text" settings available in the BIOS. These controls should be more than enough for most users.