Hello, I just threw my new rig together and was debating getting a second fan to do a push-pull configuration with my cooler master hyper 212+. I was going to set it up so that the the heat sink pointed upward, the lower fan would pull in air and the upper fan would push out the air toward the two 140mm exhaust fans I have at the top of my CM690 II case. The problem I ran into is that my motherboard, an MSI 890FXA-GD70, only has one 4-pin fan connection on it. I was under the impression that it is important in a push-pull for both fans to be moving near identical amounts of air, so it would be best if they were both being controlled by the motherboard's cpu-fan port. I think I can get around this by using a splitter cable so that I could attach them both to the 4-pin cpu-fan connector, however would there be enough power flowing through that connection to run them both?
Yep, the average fan draws very little current in comparison to the max current the mobo can handle. Instead of getting a splitter cable I am considering using 2 of arctic coolings F120 PWM fans with the PST (PWM sharing technology) so that both fans can work off the same PWM signal and equal air flow. I am unsure about if you have to have the same airflow for each fan.