Regarding fan noise

[mclaren85]

I just wanted to know something, does the fan noise come from the bearing or the turbulent air?
And if the manufacturers change the wing type, (like noctua does) will they also effect noise in a positive way?

 

[nomdeplume]

Everything effects noise.

 

[leonavis]

I just wanted to know something, does the fan noise come from the bearing or the turbulent air?
And if the manufacturers change the wing type, (like noctua does) will they also effect noise in a positive way?

Depends what kind of noise. Can you be more specific?

 

[Bill_Bright]

I just wanted to know something, does the fan noise come from the bearing or the turbulent air?

Yes.

It also comes from the moving air particles banging into each other, banging into the fan cage and case vents, and heatsink fins.

 

[Shrek]

I just wanted to know something, does the fan noise come from the bearing or the turbulent air?
And if the manufacturers change the wing type, (like noctua does) will they also effect noise in a positive way?

I'd say the air dominates for a sleeve bearing, but a ball bearing can get noisy with wear.

If you want to cut noise (without losing flow) use many large fans and have the fans under BIOS control.

I'd also avoid dust filters as to get the same flow the fans would need to run faster.

 

[Bill_Bright]

but a ball bearing can get noisy with wear.

They all can, and will.

 

[mclaren85]

Depends what kind of noise. Can you be more specific?

I mean normal fan noise, which increases with the rpm

Yes.

It also comes from the moving air particles banging into each other, banging into the fan cage and case vents, and heatsink fins.

Is there any way to decrease it with different designs?

 

[Bill_Bright]

Sure but then it gets into the science and engineering of better designs. Remember, a fan blade is a propeller which essentially is a wing, with a twist. And there are all sorts of characteristics involved in designing a wing and they vary depending on goals, including lift, speed, noise, and no doubt more. I am not an aeronautical engineer so way over my head.

Then besides blade design, there the number of blades, length of the blades, width, pitch, and rotation speed. The fan's cage/housing impacts air flow, thus noise. And then the case's vent does to.

The bearing design matters but there is no perfect design that is ideal in all characteristics. That is, there are pros and cons for each. Then there is the manufacturing quality and technique. A ball bearing that is not perfectly round or smooth is not going to be very quiet, or last long.

Sadly, it cost more to make a quality fan, but even more sad is buying the most expensive does NOT ensure the best quality.

Still, users must not lose site of the primary goal of a cooling fan and that is to move massive amounts of air. If it can do that quietly, so much the better.

Oh, and a quality case can go a long way in suppressing fan noise too. As can anti-vibration mounts.

 

[leonavis]

I mean normal fan noise, which increases with the rpm

That's rather the airflow

Is there any way to decrease it with different designs?

A design can only do that much. A 180mm-fan as found in the Torrent case can move huge amounts of air at low noise (low RPM), not because it's designed particularly well, but since it's huge. More and bigger fans can be operated less noisy.

The difference between a good cheap 140mm fan (Arctic p14 max for example) and a good expensive 140mm fan (Noctua NF-A14 G2 for example) isn't too big in terms of performance and noise, but a difference does exist.

If you want less noise at same performance however, get more and bigger fans and operate them with less RPM. If you really wanna overdo it get an external 400*400 radiator and equip it with Noctua NF-A20. Great performance and the fans won't be audible. Expensive and needs a lot of space though...

 

[Hardcore Games]

I put new fans in my old Dell XPS 15 9570 which is 8th gen i7 with GTX 1050 Ti 4GB. I also cleaned the cooler assembly and used MX-6 and reassembled. Now the machine is far less noisy and CPU/GPU temperatures are lower too. Fans are audible as the machine does not seem to support PWM fan control. No big deal as the fans are fresh and work great.

My Dell uses two different fans but they pop in easily and two screws secure them. The power cable popped in easily too.

 

[Zach_01]

I just wanted to know something, does the fan noise come from the bearing or the turbulent air?
And if the manufacturers change the wing type, (like noctua does) will they also effect noise in a positive way?

A bit of both like others said
Maybe with most of middle/high cost fans at lower/middle rpm the air flow is more audible and near top end rpm the motor noise takes over.

Many fan manufacturers do already put a lot of R&D on wing shape

 

[cvaldes]

It's worth pointing out that blade geometry has a big influence on various performance metrics. Different designs are applicable based on size, rotational speed, durability, purpose, etc. Noctua has 3-4 primary blade designs for their PC fans: the F-series is for static pressure, the S-series for moving air at slower rotational speeds (and quieter operation), the A-series are designed for balanced performance.

Note that a helicopter rotor is designed differently than a propellor for a large turboprop which is in turn different than a smaller aircraft like general aviation Cessna or a balsa toy airplane powered by a rubber band.

For sure some of the noise is from the moving air itself. If you've ever sat in a motor vehicle (automobile, truck, train, airplane, boat), you'd recognize that some of the sound is coming from the moving air, some of it is coming from the mechanism. And there are plenty of situations where there is no motor to be found including the wind, the swish of a tennis racket or fly swatter.

Here's another example of naturally occuring sound from the movement of air:

Why do mosquitoes buzz in our ears?

Does that make them easier to swat?

www.livescience.com

that has no motorized mechanism. Remember that any beating wing or fan blade is disrupting air and causing turbulence.

 

[DirtyDingusMcgee]

Is there any way to decrease it with different designs?

Sure. Is there a magic configuration that will make them completely silent. Probably not.

 

[Shrek]

I imagine one day an anti-noise add-on.

There is also the trick of asymmetric fans to spread the sound over the spectrum, which is perceived by the brain as less noisy.

Thicker blades also help to reduce vibrations

Swept blades (for high static pressure) probably lead to more vibrations

 

[mechtech]

A new fan 1m+ away from you I’d guess 99% air turbulence noise and 1% bearing and motor noise.
Having said that I have had PWM fans with audible motor noise over a meter away which manifests as clicking and in some cases “hunting” where the fan is constantly moving rpm, both are annoying and now those new fans sit on the shelf.

 

[blinnbanir]

The Quality of the Design. Noctua used to make the quietest fans but people that know have Arctic, Phanteks and Thermalright to rely upon. 120mm will always have a potential to be louder than 140mm and fan noise can effect how much you enjoy your PC. PWM is something worthy enough to take the time to engage fully. GPU fans are the worst but As Rock seem to have quiet fans.

 

[freeagent]

It depends on the fan, usually with high performance fans you will hear the motor noise, wind noise, and turbulence. Mid range fans will let you hear air movement, and maybe a little motor noise. The lowest quality fans might be quiet, but move very little air, and at full speed you will hear motor noise because of the lack of airflow lol

 

[Shrek]

The number of motor poles probably also plays a role.

In the end I went with a three pack of the Antec T30 and was so pleased that I got a second set for the same computer.

The main noise ended up coming from the CPU cooler which I also replace with one that had a copper core to reduce hunting.

 

[Athlonite]

I just wanted to know something, does the fan noise come from the bearing or the turbulent air?
And if the manufacturers change the wing type, (like noctua does) will they also effect noise in a positive way?

The biggest culprit of noise in your case will be the CPU heatsink you should replace it with a decent tower cooler of 120 ~ 140 mm either Arctic or Thermalright both make great HSF's and they're not expensive
don't get me wrong the Wraith is a good stock cooler but it's loud as fuck when things get hot because it has a small fan that spins at high speed in order to push enough air

 

[mclaren85]

The biggest culprit of noise in your case will be the CPU heatsink you should replace it with a decent tower cooler of 120 ~ 140 mm either Arctic or Thermalright both make great HSF's and they're not expensive
don't get me wrong the Wraith is a good stock cooler but it's loud as fuck when things get hot because it has a small fan that spins at high speed in order to push enough air

The biggest noise is coming from the intake fans. There are 4 of them and spinning at 1200-1700 rpm. 3 of them MSI and one is arctic. It seems to me arctic is louder.

 

[leonavis]

The biggest noise is coming from the intake fans. There are 4 of them and spinning at 1200-1700 rpm. 3 of them MSI and one is arctic. It seems to me arctic is louder.

1200 is pretty high RPM, it's no wonder that they are audible.

 

[Athlonite]

It seems to me arctic is louder.

That's probably because it's pushing more air than the shitty MSI fans at the same speed if you wanted to you could limit all fans to a max of 1500rpm that would bring noise down quite a bit.
But at the end of the day using a stock HSF on a 3900X is just daft if you don't need to it's all good to use one until you can afford a better HSF but to continue using it not so much
the fan is small the heat transfer area is small so inorder for your stock HSF to maintain a reasonable temps and core clocks it needs to do more work and the mobo will run all fans faster as they'll be linked to CPU temp, The cooler you keep your CPU the less noise the case fans will make because they'll run slower

 

[TairikuOkami]

And if the manufacturers change the wing type, (like noctua does) will they also effect noise in a positive way?

I have always replaced case fans with Noctua and it paid of, I locked them at 700rpm, they lasted a decade. My current ones are PWM, they run at 600rpm automatically. Everything is cool and quiet.
I lock GPU's FPS to 60 or else it is loud as a turbine @100%. As mentioned, if fans have to push though something, it can make various sounds. I prefer to clear all the way and throw away everything.

 

[leonavis]

Is that the MSI Armor design? I had that too, RX580, very loud. Changed dramatically with new (and good) paste and a slight undervolt.

 

[Bill_Bright]

I mean normal fan noise, which increases with the rpm

That's rather the airflow

Yes and no. Sure, if you increase the RPM thus increasing the air flow, the noise from the air molecules hitting each other and things in their path will increase. But increasing the RPM also increases actual motor noise too - especially if the bearings are already worn and making noise.

The biggest noise is coming from the intake fans. There are 4 of them and spinning at 1200-1700 rpm.

Why do you have so many intake fans? That alone may be much of your problem. Intake fans tend to be located in front, closer to our ears. Being mounted directly to the case allows any sound and vibrations from the fan to be transferred to the case. Case's are cavernous metal boxes where sounds and vibrations that make sounds can reverberate throughout the case, effectively amplifying those sounds.

Why do you have them spinning so fast? Have you tried a speed controller and setting it to 500 - 600 RPM to see how it affects cooling?

How many exhaust fans do you have? You want a "slight" over or positive pressure in the case. That means slightly more coming in than going out. This ensures incoming air only comes in through the [hopefully IMO filtered] intake vents instead of every crack, crevice, and unused port in the computer.

If you have too much positive pressure (not enough exhausting out fast enough) your speeding fans are, in effect, blowing into a solid wall of stagnant air. That can make a LOT of noise.

So what do you have for exhaust? You can count the PSU fan too UNLESS it has its own, dedicated input vent.

Are we talking about the Velox 100P Airflow noted in your System Specs? If so, according to the specs, it comes with 3 x 120mm intake fans in front and just a single exhaust 120mm fan in back. So how do you have 4 "intakes"? Did you turn the rear fan around or add more?

Another big problem is the fact these are 120mm fans. Smaller fans have to spin faster to move the same amount of air as larger fans. Faster RPM, louder the fan noise.

If the Velox, the PSU is mounted in its own chamber and therefore, is useless when it comes to helping out with case cooling.

I see no mention at all in the specs, product description, or the manual about sound or noise suppression. And sadly, the only fan control appears to be for the ARGB lights, not speed.

Your case (if it is that Velox 100P) supports 3 x 140mm fans in front, and 2 x 140mm fans up top. Sadly , it only supports the single 120mm fan in back. That is not a good design for cooling, IMO.

If fan noise is a concern for you, you clearly bought the wrong case!

If me, I would start by getting rid of the front 120mm fans and replace them with 2 quality 140mm fans. And I would get a fan speed controller, one that allows you to control each connected fan individually. If the rear 120mm is noisy, replace it with a high quality 120mm. IF you have space for a thicker fan (the standard is 25mm) get one. Wider blades can scoop up and push more air. If your temps are too high with just those fans, or if you have to push the front fans to maximum speed, I would add a 140mm fan up top, in the back position, as an exhaust and, crossing fingers and toes, hope that keeps the innards properly cooled.

If not, shop for a new case. Your priority should be cooling, noise suppression, aesthetics, in that order. I like Fractal Design. Their fans are great too.

I personally don't understand that MSI Velox. It seems they put aesthetics first, then cooling a distant second, and noise suppression no where on the list.