The Current Top Fan?

[PartEleven]

What's the absolute quietest 120mm fan (undervolted or not) available that money can buy right now? I know the Nexus 120mm has been a favorite for a while, but I'm not sure how some of the newer Noctua or Scythe slipstream compare to it. I've been using Yate loon D12-SL12 fans for a while now, and they are definitely very quiet once undervolted. However, I'm still hearing some noise coming from my computer. I believe it may be just the woosh of air moving, but I would like to buy an exceptional fan I could use as a real-world reference and benchmark.

[Bluefront]

This is a common question we hear asked frequently......with no real answer. I have a few dead-silent fans sitting on a shelf somewhere. The blades won't move, and that is the only way to get a 100% quiet fan.

After that....bearing noise is critical at low rpms, not to mention the fan controller itself. Some fans click with a PWM control. And you have to determine what CFM you need. The airflow noise from 10CFM is obviously going to be less than from a 20CFM fan. And there's the start-up problem. Some fans will be quiet at 5V, but won't start that slow.

So....come up with some guide-lines. How much CFM do you need? What sort of fan speed control are you using? Will the fan be used as a case fan? Will it be blowing into a tight fin-pack on a heat-sink, etc.

Scythe sells numerous quiet fans....they're hard to beat, but make noise with PWM fan control, as do many others.

[NeilBlanchard]

Hello,

In my opinion, the Scythe Slipstream 800RPM is the best fan right now. The 500RPM is the quietest at 12v (no surprise, really).

[DragonOptical]

Hello,

In my opinion, the Scythe Slipstream 800RPM is the best fan right now. The 500RPM is the quietest at 12v (no surprise, really).

I find it strange that you say that, because the Scythe S-FLEX 800RPM (8.7dBA) is quieter than the Scythe Slipstream 800RPM (10.70dBA).
Though the Noctua NF-S12-800 (8dBA) is even quieter (well, in theory).

@PartEleven: you probably allready know this, but SPCR has a Recommended Fans list

[jhhoffma]

I find it strange that you say that, because the Scythe S-FLEX 800RPM (8.7dBA) is quieter than the Scythe Slipstream 800RPM (10.70dBA).
Though the Noctua NF-S12-800 (8dBA) is even quieter (well, in theory).

Are you quoting manufacturer specs? If so, here's how much manufacturer specs mean in regards to how a fan performs/sounds....................................................
....
....
Still waiting? Too bad, they mean nothing. Most of them are outright lies because the average user means nothing. The only way to get 8dB is in an anechoic chamber, no one here (even the SPCR Lab) could manage that.

The S-Flex is not a bad fan, but for the same RPM you get much better airflow with the Slipstream. It is a superb fan, bar none. Even the 1200rpm version is pretty quiet below 1000rpm.

[jaganath]

The only way to get 8dB is in an anechoic chamber, no one here (even the SPCR Lab) could manage that.

actually I doubt even for an anechoic 8dB is realistic. for example in Nexus's test facility 15dB(A) is the noise floor:

http://www.nexustek.nl/NXS-120mm-pwm-fa ... -quiet.htm

and that's the standard, ISO-3745/ISO-7779 setup.

a good quote from that page:

In the market there are a lot of unrealistic dB(A) value-claims which are often calculated by means of extrapolation. This in fact does not give a realistic view of the fans noiselevel performance.

[Felger Carbon]

In my opinion, the Scythe Slipstream 800RPM is the best fan right now. The 500RPM is the quietest at 12v (no surprise, really).

I find it strange that you say that, because the Scythe S-FLEX 800RPM (8.7dBA) is quieter than the Scythe Slipstream 800RPM (10.70dBA).

If you measure at equal RPM, you're right. If you measure at equal voltage, you're right. If you measure at equal airflow (CFM)...

Just exactly what do you consider equal conditions for two different fans?

edit: corrected brain fart

[blackworx]

The S-Flex is not a bad fan, but for the same RPM you get much better airflow with the Slipstream. It is a superb fan, bar none. Even the 1200rpm version is pretty quiet below 1000rpm.

...But bear in mind the Slipstream is a sleeve bearing fan and won't be as quiet if installed horizontally (e.g. P18x top exhaust).

[PartEleven]

This is a common question we hear asked frequently......

I don't have a particular CFM I require. Obviously I understand that any fan will generate airflow noise, even if the fan bearing is dead silent. What I'm really looking for is the current fan with the lowest bearing noise for a given CFM.

It sounds like the Scythe slipstreams are quite popular now, but how does the old standby, the Nexus, compare to it?

[NeilBlanchard]

Greetings,

...But bear in mind the Slipstream is a sleeve bearing fan and won't be as quiet if installed horizontally (e.g. P18x top exhaust).

I wonder where this horizontal thing comes from? As far as I'm concerned, it's a myth.

There is one fan (GlobalWin NCB) that I'm aware of that slows down when positioned to blow downwards -- but in a PSU or in the top of a P18x case, the fan blows upwards.

The SPCR review of the Copper Ninja compares the 800RPM Slipstream with the Nexus 1000RPM:

http://www.silentpcreview.com/article805-page5.html

The Slipstream is quieter (17-18dBA) vs the Nexus (17-23dBA), especially from 7v-12v range.

[Bluefront]

I also wonder about that orientation/sleeve-bearing thing. I do know that many/most fans will spin faster in certain orientations. This is apparently due to lessened friction on the bearings in a certain orientation. I've never found the "best" way to position all sleeve bearing fans however. It seems to vary from fan to fan. But ball bearing fans act this way also. So who knows?

If you can get a sleeve bearing fan to start and run at 500 rpms, any brand will be fairly quiet with an analog controller. Slip-Stream fans are hard to beat..... but the S-Flex fans are also in the same league with presumably better bearings.

[jaganath]

...But bear in mind the Slipstream is a sleeve bearing fan and won't be as quiet if installed horizontally (e.g. P18x top exhaust)......
I wonder where this horizontal thing comes from? As far as I'm concerned, it's a myth.

i've a Nexus 120mm installed horizontally (blowing downwards) on my CPU, silent as a church mouse, but then it's running at lowest possible voltage, ~5V. the evidence for increased noise from sleeve fans in horizontal orientation is sparse, but it probably does decrease the fan lifetime somewhat:

http://www.silentpcreview.com/article63-page1.html
http://www.nmbtc.com/pdf/forum/ball.pdf

[jhhoffma]

My Slipstream 800rpm (12v) is now ziptied to my GPU, mounted upside-down and horizontal. It sounds no different from when it was mounted vertically in the exhaust port of my SLK3000B.



It's a bit of overkill (a 500rpm would be plenty here) but it's what I have. I always believed the "noisier when horizontal" myth too until I actually had some sleeve bearing fans. Once I compared them to some of my ball-bearing fans, I realized that the noise from my B/B fans increased more when hung upside down than the sleeve bearing fans. It was a small sample set, granted, but it was enough to convince me that it's not a sole determining factor. I do, however, believe what jaganath claims about lifetime suffering for it.

[Plekto]

actually I doubt even for an anechoic 8dB is realistic. for example in Nexus's test facility 15dB(A) is the noise floor:

So they probably measure it as 8dB above their noise floor and suspended from a string or something. No case, no back-pressure... I know Silenx must be doing this sort of thing, because their fans are noisier than many non-name brands. Their measured values and advertised ones are just too far apart from each other.

Thermaltake, Zalman, and a few others seem to be closer to reality. Their fans run close to what is says on the package. Few things at full speed will be close to 20dB. 25 is more common. That said, 30db is twice as loud to our hearing as 20Db, and every two sources at the same dB adds about 3dB.

eg: One 25dB fan = 25dB Two of them =28dB.

The Thermaltake Silent Wheel is especially sweet if your case can fit it, btw. It's and odd animal, but it does give good CFM and low rpms. But most cases won't work with it.

[PartEleven]

Thanks for the input guys. I went with the Scythe slipstream 800rpm since the vendor I was buying some other stuff from doesn't sell Nexus fans. Maybe I'll try the Nexus another day when the chance comes up. Right now ordering just that one fan doesn't seem worth it for the shipping costs.

[jhhoffma]

Good choice, you won't regret it...unless the fan is damaged.

[blackworx]

Greetings,

...But bear in mind the Slipstream is a sleeve bearing fan and won't be as quiet if installed horizontally (e.g. P18x top exhaust).

I wonder where this horizontal thing comes from? As far as I'm concerned, it's a myth. I wonder where this horizontal thing comes from? As far as I'm concerned, it's a myth.

Yeah sorry, apologies for the FUD!

Myth or not however, what I know for a fact is that all 4 Yate Loons I bought recently and subsequently returned for being faulty were definitely noisier when held horizontally. They were clearly not working to spec., most likely due to poor bearing tolerance, so you could either discount them completely and say it was a freak occurrence, or you could say they were an extreme example of a typical phenomenon. Personally I would tend to go with the latter but, as I'm sure anyone will agree, the difference is going to be practically non-existent with a brand new working fan anyway. Most reports I've seen refer to old fans, where a million and one other factors probably come into play as well.

[hophophop]

There is a very qualified french reviewer who explains in his noctua review that sleeve bearings fans are not designed to work in horizontal position.


http://www.cooling-masters.com/articles-39-3.html


"Un ventilateur à palier lisse ne devrait normalement être monté qu'avec son axe vertical et la tête vers le haut ! Avoir l'axe horizontal induit une force due à la gravité qui tend à le faire frotter toujours aux mêmes endroits sur le palier et ça réduit irrémédiablement sa durée de vie. Le mettre tête en bas peut produire plus de bruit car la mécanique n'est pas forcément adaptée pour être retournée et ça s'entendra sur les modèles Noctua. Ca peut frotter sur l'arrière, le rotor étant plus ou moins centré en hauteur par l'action du champ magnétique entre l'aimant circulaire et la partie métallique du moteur. On risque aussi d'éjecter l'huile car elle coule par gravité et rien ne la retient. Cela peut se voir en regardant l'intérieur du rotor, il en sera couvert."

May be someone with a better english that me can translate it. I'll just try to sum up. He says gravity makes the sleeve bearing rub always at the same spots and that it shortens his life. Placing the head of the fan at the bottom may make the fan noisier because the mechanical parts are not designed to work that way and it will be heard on the noctuas. The rear can rub, the rotor being loosely centered in height by the magnetic field action and the metallic part of the motor. Oil may be lost because gravity makes it leak. You may see it by looking at the inside of the rotor, it will be covered with oil.

[NeilBlanchard]

Hello,

Well, I'm pretty sure that it can also be shown how ball bearings would have problems, as well. A poorly made bearing of any sort will be problematic. And conversely, a well made bearing of any sort will be quiet and last a long time.