2 fans vs 1 fan on CPU heatsink.

[Prasad001]

I'm thinking about buying new CPU cooler (Gammaxx 400). currently using and wraith stealth cooler with 3600x. Reason I'm thinking to change CPU cooler is noise (& temps). Gammaxx 400 is good CPU cooler and can lower CPU temps. problem remaining is noise.I know that adding extra fan does not improve performance. But does it reduce total amount of noise ?

[Bruno_A]

The Gammaxx 400 is a good cooler (I owned one, myself), and you can probably get away using only one fan at low RPM and have happy days, with low noise, depending on what fans you using. Two fans will not really give you a performance increase (maybe a couple degrees, but probably not even that), however, I am not sure if you're able to use two fans at minimum RPM, instead of one spinning slightly faster. Just try one fan, at the lowest RPM possible and see if the temperatures are good.

[Bombastinator]

another (more verbose) way of saying what @bruny06 said:

 

2 fans vs 1 fan isn’t about more cooling it’s about noise and fan rpm.  You likely won’t get better temps from multifan at high rpm.  All a second fan does is make the first work a bit less hard so you can lower its rpm a bit.  Sometimes this matters for noise (and only noise) and sometimes it doesn’t.

My memory is that there are (or used to be) sort of magic rpm numbers for different fans regarding noise.  It varies primarily by fan size, but also slightly by blade design. There will be a number of RPM below which a fan makes almost no noise.  2 fans make more noise than 1 fan, but the difference in noise level is so great between above and below that magic number, that if you have 2 fans below that number they will together make less noise than one fan above it.

 

my memory is that for 120mm fans that number  was (10 years ago) near 800-900 rpm, variable a bit by a particular fan design. (Mostly it’s about the sweep angle of the leading edge.  Bumps and textures mean very little). The number for 140mm would have been lower.

 

What @bruny06 seems to be saying is that because the magic number is close to the minimum possible fan speed you may not get much out of a second fan with this cooler.  It might even be worse.

 

Fans are a bit different now.  They seem to have more blades and more aggressive sweeps.  This may have changed things.  
 

The thing about fans though is they’re propellers and most of the physics for propeller design was worked out long long ago back when tiny performance differences in propeller aircraft meant life or death for nations.  It can’t have changed all that terribly much.

[MartinKweh]

experience on gammaxx 400, 1 fan is enough. 2 fan doesn't help that much. 2 fans works on thick heat sinks with dense fins. but with heat sinks with fins not thicker than a 212. 1 fan is good enough. if its like Bequiet! shadowrock 2 where its literally so thicccccc that the c i put is not enough, i think 2 fans will help it a lot.

[LogicalDrm]

Rather than thinking if you can get performance upgrade from second fan, go for bigger/better cooler instead. The gains on small heatsinks are even lower than with 140mm towers.

[WoodenMarker]

Adding another fan should increase cooling performance but the temp drop is generally small unless cooling was insufficient. 

A second fan can allow for similar performance but lower noise through lower fan speeds. That being said, you're usually better off getting a better cooler to begin with. 

[Prasad001]

On 11/16/2019 at 2:00 AM, LogicalDrm said:

Rather than thinking if you can get performance upgrade from second fan, go for bigger/better cooler instead. The gains on small heatsinks are even lower than with 140mm towers.

 

On 11/19/2019 at 3:28 AM, WoodenMarker said:

Adding another fan should increase cooling performance but the temp drop is generally small unless cooling was insufficient. 

A second fan can allow for similar performance but lower noise through lower fan speeds. That being said, you're usually better off getting a better cooler to begin with. 

reason for asking about 2 fans, because after building pc ,I don't have much left. So I have to buy cooler on cheap ...but I don't what noise either.

[WoodenMarker]

17 hours ago, Prasad001 said:

reason for asking about 2 fans, because after building pc ,I don't have much left. So I have to buy cooler on cheap ...but I don't what noise either.

Did you already have the cooler?

If you're looking to save money, just don't get a second fan. For the price of the cooler and a second fan, you can generally get a better cooler instead. 

[Prasad001]

On 11/21/2019 at 11:08 AM, WoodenMarker said:

Did you already have the cooler?

If you're looking to save money, just don't get a second fan. For the price of the cooler and a second fan, you can generally get a better cooler instead. 

Any suggestions?

[WoodenMarker]

On 11/23/2019 at 8:26 AM, Prasad001 said:

Any suggestions?

Can you link us to where you're shopping? What kind of pricing are you looking at for the Gammaxx 400?

[Prasad001]

I'm looking to on 2 sides. Amazon and mdcomputers.in .on mdcomputers, I will get Deepcool Gammaxx 400 Blue 120mm CPU Air Cooler With Blue LED (DP-MCH4-GMX400) for Rs.2250 on amazon for Rs.3000. My max budget for CPU cooler is around Rs.3200. (I'm from India)

[Midnitewolf]

The Arctic Freezer 34 Esport DUO looks pretty good for a budget option with two fans.  Good review and looks good too.  Not sure what the price is in India but in the US it is around $35-$40 so on the lower end of the spectrum.

[Prasad001]

4 hours ago, Midnitewolf said:

The Arctic Freezer 34 Esport DUO looks pretty good for a budget option with two fans.  Good review and looks good too.  Not sure what the price is in India but in the US it is around $35-$40 so on the lower end of the spectrum.

Cooler you suggested is really good ,but problem with that is in my country it is double the price you specified .So it is way out of my budget. If I had bigger budget ,I would definitely go for Arctic freezer 33.

[WoodenMarker]

On 11/26/2019 at 9:56 AM, Prasad001 said:

I'm looking to on 2 sides. Amazon and mdcomputers.in .on mdcomputers, I will get Deepcool Gammaxx 400 Blue 120mm CPU Air Cooler With Blue LED (DP-MCH4-GMX400) for Rs.2250 on amazon for Rs.3000. My max budget for CPU cooler is around Rs.3200. (I'm from India)

The Gammaxx 400 seems like the best option for the price and is hard to go wrong with. 

Make sure to quote a post or tag a member when replying or else they won't get a notification that you replied to them.

[Prasad001]

On 11/28/2019 at 1:52 AM, WoodenMarker said:

The Gammaxx 400 seems like the best option for the price and is hard to go wrong with. 

Make sure to quote a post or tag a member when replying or else they won't get a notification that you replied to them.

ok. thanks for advice.

 

[Krisalex]

Baiscally of all i was reading so far you must have either a big-big single tower heatsink, two towers heatsink, or really inferior fans to justify all this trouble. Every half decent high static pressure fan is designed by original intent and design to push air with enough force (pressure) to move between the fins, trough the whole depth of the heatsink, as for syncing both fans keep in mind most fans are made with some percentage usually about 10% of different rpm as manufacturing tolerances, this can show its evil. Basically the faster rotating fan needs to ne pull fan to sustain the airflow. A good, high quality high-static pressure like noctua or others in the same category as noctua will push the air trough the whole heatsink with sufficient pressure to be effective. On top of that you will increase noise and get into more issues, to double the connections. If i was you, i was about to use 1 push high static pressure fan from Noctua's industrial line of fans. You will have relatively the same noise and power comsumption between 1 industrial and 2 consumer fans, but the airflow and the static pressure of one industrial fan will exceed the combined effort of both consmer fans for relatively the same noise. And as for the noise, big noise values are only when the fan is working at full power, but in pwm case, the fan self regulates to minimum useful rpm, negaring large part ot he noise. If a fan reaches full rpm, reducing rpm and noise. This also means your compiter is deep in the trouble, if a 3000 rpm fan is revving up to full power and your priorities will be other than a noisy fan, trying to save your pc from overheating. Keep in mind an industrial fan pushes more air - a bigger airflow with higher static pressure, compared to a pair of consumer fans, so you will have better cooling with one push fan, industrial grade fan at the same rpm, compared to 2 consumer fans basically forcing the fan to slow down and reducing the chance to rev up. If it rev up it will be less rpm that the pair of consumer fans.