be quiet silent 3 - which type?

[wizard]

Want to put 2 x 140mm top fans in be quiet dark base 900 pro rev 2 case.

There are 2 available:

be quiet silent wings 3 140mm and be quiet silent wings 3 PWM. Which one should I opt for?

There are 3 140mm PWM fans in the case (2 in front / 1 at back)

Should I opt for PWM?

 

[wizard]

Generally using top fans doesn't help case airflow and often hurts it. I think you can use 3x 140mm front intakes and block all openings not covered by fans in front mounting plate. This will stop the air front fans are pushing into case from leaking back in front and move more air through case. I've found removing all PCIe back slot covers (even vented ones) improves front to back airflow around GPU and thus lowers temps. It also helps keep the heated exhaust coming off of GPU from moving up into airflow to CPU cooler and thus lower temps on CPU too. The link below is to basic guide to case airflow and how airflow works might be of interest"
https://forums.overclockers.co.uk/threads/help-with-fan-setup.18763212/#post-30354296

Thanks. Very informative.