One fan vs. two fans with the Corsair H80i cpu liquid cooler

[BEARaj87]

Hi everyone.

I'm in the midst of installing my first cpu liquid cooler into my carbide300r chassis. I'm installing it on the back panel with a push/pull configuration exhausting the hot air out of the chassis. Unfortunately the H80i radiator and its two fans are very large when stacked up together and it causes some interference with the heat sink. I'm thinking of just using one push fan.

I'm hoping someone can tell me about the performance difference when using two radiator fans vs. one. I'm planning overclocking an Intel i7 930 chip and am hoping I can get away with one fan.

Thank you very much for your help and information!!

 

[Gathorisx]

2 fans is always better than one (in most cases) and having a push/pull config on a h80 would help, but it's not a very significant change, so yeah you can get away with one fan!

 

[nukemaster]

I actually did some testing on that exact cooler with NF P12 fans.

Room 21c 2x NF P12
Core 1 52 - 21 = 31
Core 2 56 - 21 = 35
Core 3 58 - 21 = 37
Core 4 57 - 21 = 36
Package 57 - 21 = 36

Room 22c NF P12 + NF P14(push, no adapter its just bolted on)
Core 1 54 - 22 = 32
Core 2 57 - 22 = 35
Core 3 59 - 22 = 37
Core 4 58 - 22 = 36
Package 58 - 22 = 36

Room 21c Single NF P12
Core 1 57 - 21 = 36
Core 1 59 - 21 = 38
Core 1 61 - 21 = 40
Core 1 60 - 21 = 39
Package 60 - 21 = 39

As you can see, the difference is not huge(5c tops).

Alternatively, if nothing gets in the way and the rear fan spot is flat, you can mount a fan outside the case on the back

Something like this.

 

[BEARaj87]

Pretty surprising, not much difference. I will likely do a similar test just to be sure, but it looks like I'm gonna go with only one fan. Thanks a lot, it's nice to see some specific temps in a real test.

 

[nukemaster]

I think the lower fin per inch of that radiator is why it can get by with less. After all even a cheap fan will push air past it without issues.

I had done some tests on the lower rad as well. It is much more dense, but with single fans the difference from a 1300 rpm Noctua NF P12 and the same speed of AP15(dropped the voltage to get near the same speed) was only about 1 degree.

I kept the AP15 because it has more headroom from its extra speed(should help when the warmer weather hits), but it has a different sound from the Noctua's for sure(Noctua's sound is deeper and less noticeable to some users) and at some speeds is louder than a slightly faster speed(to be fair some of my NF S12's are the same like 800 was quieter than 740 because of a vibration they develop at that speed).

I am still a big fan of fan on the back of the case if it fits