[SOLVED] fans: 3x120mm vs 2x140mm

[rl3857]

Hi, I want to buy a Phanteks P600s for my first PC build and find it can mount either 3x120mm fans or 2x140mm fans on the top. So which one has a better performance? My CPU is 9700k and I plan to do some overclocking. Besides, is a 240mm aio enough for the 9700k or I need to buy a 280mm / 360mm?

Here's the part list:
Case: Phanteks P600s
CPU: Intel i7 9700K
Video Card: MSI RTX 2070 Super Gaming X Trio
CPU Cooler: NZXT Kraken X52
120mm Fan: be quiet! Silent Wings 3 PWM High-Speed 120mm
140mm Fan: be quiet! Silent Wings 3 PWM High-Speed 140mm

Thanks!

 

[Phaaze88]

Depends on where you want to mount the radiator, and no, it doesn't matter whether it's in the front or up top.
Their 120mm Silent Wings 3 appear to be flat out superior compared to the 140mm model:
https://www.bequiet.com/en/casefans/723

SILENT WINGS 3 | 120mm PWM high-speed silent high-end Fans from be quiet!

be quiet!

www.bequiet.com

-If the radiator is being mounted in the front, then do 2x 120s at the top - don't bother with a top-forward fan, as it'll just pull cool air out of the case before it even does anything.
-If mounting it up top, then 3x 120s in the front.
-Rear: 120mm

The 9700k is more forgiving than the 9900k, so I think you could do with either 240/280mm. 280mm if you plan to overclock it though.

 

[rl3857]

Depends on where you want to mount the radiator, and no, it doesn't matter whether it's in the front or up top.
Their 120mm Silent Wings 3 appear to be flat out superior compared to the 140mm model:
https://www.bequiet.com/en/casefans/723

SILENT WINGS 3 | 120mm PWM high-speed silent high-end Fans from be quiet!

be quiet!

www.bequiet.com

-If the radiator is being mounted in the front, then do 2x 120s at the top - don't bother with a top-forward fan, as it'll just pull cool air out of the case before it even does anything.
-If mounting it up top, then 3x 120s in the front.
-Rear: 120mm

The 9700k is more forgiving than the 9900k, so I think you could do with either 240/280mm. 280mm if you plan to overclock it though.

Thanks for your reply! So is it better to mount the radiator to the top? And why is their 120mm fans better that the 140mm? I'm just a beginner and thought the bigger the better.

 

[Phaaze88]

Thanks for your reply! So is it better to mount the radiator to the top? And why is their 120mm fans better that the 140mm? I'm just a beginner and thought the bigger the better.

Personal preference, really, so it's up to you.

View: https://www.youtube.com/watch?v=YCZ5iP5cu8g


Usually, 140mm delivers more airflow than 120mm at certain speeds, but in this case, I believe be quiet! under-engineered their 140mm - or perhaps they over-engineered their 120s!
Open up the above pages in 2 separate windows, click on the Technical Data tab, and scroll all the way to the bottom. Look at the posted fan curve for each.
Now, go back and forth between the 2 windows. Notice how the 140mm never surpasses the 120mm at any point.
[These images are very handy. It's too bad not all manufacturers do this for their fans.]