Question Problem with Be Quiet Silent Wings Pro 4 120mm

[dolama72]

Hi, I purchased 3 of these and are fantastic, sileent and powerful. Howver I noticed that at 100% they reach 2800 RPM max, not the 3000 nominal.
2 of them are mounted as case fans connected to 1 mobo header with an Y cable.
1 is used on the AIO radiator, connected to the CPU Fan header on the mobo.
All 3 are switched to UHS (hardware switch on the fan) but at 100% they reach only 2800 RPM.
No matter how I control them (from BIOS or with 3rd party software like Fan Control) they don't reach 3000 RPM.
Any ideas?
MoBo: Asus Rog Strix B360-I Gaming

Thanks!

 

[In2Photos]

Only thing I can say is that the website says "up to 3000 RPM". Or the motherboard is not capable of 100% PWM. Are you expecting the extra 200 RPM to achieve something specific?

 

[BoomerD]

• Optimized fan blades for the highest performance on radiators and heat sinks
• Speed switch allows changing maximum PWM speed between medium-speed, high-speed and ultra-high-speed (up to 3000 rpm)

Other than the "up to 3000 RPM" bit, I don't know the answer. Is your board putting out the right voltage to the fan header? Could the "Y" cable be the problem? Have you tried just ONE fan connected to that header?

 

[dolama72]

Only thing I can say is that the website says "up to 3000 RPM". Or the motherboard is not capable of 100% PWM. Are you expecting the extra 200 RPM to achieve something specific?

Not really, actually I tend to use low noise fan speed profiles.
But you know, it’s just bothering me because they should run at 3kRPM! And because they’re expensive.

 

[dolama72]

Other than the "up to 3000 RPM" bit, I don't know the answer. Is your board putting out the right voltage to the fan header? Could the "Y" cable be the problem? Have you tried just ONE fan connected to that header?

The CPU fan is running solo, so I guess the issue is not the Y cable. I have the impression that somehow the motherboard does not “conceive” the 3k RPM. But it should not be a voltage issue. The two fans on the chassis fan header with Y cable run at the same max speed of the solo fan on the CPU fan header.
Maybe some Bios settings?
I tried to play around with that as well but could not find any “max RPM“ limit option/

 

[BoomerD]

The CPU fan is running solo, so I guess the issue is not the Y cable. I have the impression that somehow the motherboard does not “conceive” the 3k RPM. But it should not be a voltage issue. The two fans on the chassis fan header with Y cable run at the same max speed of the solo fan on the CPU fan header.
Maybe some Bios settings?
I tried to play around with that as well but could not find any “max RPM“ limit option/

It's always possible that the software just isn't reading the fan speed correctly...

 

[BoomerD]

Since it's an ASUS board, you might find the answer here:

CPU fan won't run at full speed

Hi, A little background to my problem. I have the asus z87m-plus motherboard and overclocked my i5 4670k to 4.4ghz @ 1.239v which I imagine is pretty average. I installed the asus AI suite 3 to play around with the clocks but have up and and uninstalled it, but not before lesson would the fan...

www.techpowerup.com

 

[dolama72]

Since it's an ASUS board, you might find the answer here:

CPU fan won't run at full speed

Hi, A little background to my problem. I have the asus z87m-plus motherboard and overclocked my i5 4670k to 4.4ghz @ 1.239v which I imagine is pretty average. I installed the asus AI suite 3 to play around with the clocks but have up and and uninstalled it, but not before lesson would the fan...

www.techpowerup.com

Thannks, but from what I see, the OP there has the problem of the fans not running at 100%, in my case they do, but the corresponding RPM is 2800 not 3000 as it should be.
I hope I could explain the issue.

I allso wrote to Be Quiet, after a couple of queestions theey asked me to seend the fan over ffor a technnical cheeck.
The point is that all of theem max out at 2800 RPM, regardleess of thee header they are attached to. It'svery unlikeely that it's a hardware fault, it must be some software limitation.

 

[BoomerD]

Thannks, but from what I see, the OP there has the problem of the fans not running at 100%, in my case they do, but the corresponding RPM is 2800 not 3000 as it should be.
I hope I could explain the issue.

I allso wrote to Be Quiet, after a couple of queestions theey asked me to seend the fan over ffor a technnical cheeck.
The point is that all of theem max out at 2800 RPM, regardleess of thee header they are attached to. It'svery unlikeely that it's a hardware fault, it must be some software limitation.

If they're running at 2800 RPM instead of 3000, they're not running at full speed. (or else the software is wrong)
Are the fan speeds wrong in the BIOS? Have you tried Speed Fan?

 

[dolama72]

If they're running at 2800 RPM instead of 3000, they're not running at full speed. (or else the software is wrong)
Are the fan speeds wrong in the BIOS? Have you tried Speed Fan?

I checked in the bios and setting QFan Control to Full Speed (i.e. fans at 100%) I read the saame 2800 RPM on all fans
I downloaded Speed Fan now but cannot get it to read the fan speed...
I'm using Fan Control software and there I can select each fan and manually force it to run at 100%: again 2800 RPM

 

[BoomerD]

I checked in the bios and setting QFan Control to Full Speed (i.e. fans at 100%) I read the saame 2800 RPM on all fans
I downloaded Speed Fan now but cannot get it to read the fan speed...
I'm using Fan Control software and there I can select each fan and manually force it to run at 100%: again 2800 RPM

Maybe try disabling Q-Fan in the BIOS for each fan, re-check.

 

[dolama72]

Maybe try disabling Q-Fan in the BIOS for each fan, re-check.

Done. No changes, other than increased RPM fluctuation at 100% (between 2760 and 2860 RPM)
I think I'll just live with it...

 

[dolama72]

Ii just wanted to thank everyone who took the time to help me out here. Thanks guys.

 

[BoomerD]

Ii just wanted to thank everyone who took the time to help me out here. Thanks guys.

Let us know what be quiet! has to say about this.

 

[dolama72]

Let us know what be quiet! has to say about this.

I decided to go a different way.
With CPU and motherboard prices going down, I am going to build a new system, including moving away from mini-ATX case and motherboard.
I will get a bigger case and fit 140mm fans instead, I will go for the same Be Quiet Silent Wings Pro 4, but in the bigger version and return all the 120mm fans to amazon.

 

[gdansk]

It isn't unusual for fan speeds to read with ±10% error of advertised RPM.
But contact BeQuiet that may be within their specifications or not.

 

[dolama72]

It isn't unusual for fan speeds to read with ±10% error of advertised RPM.
But contact BeQuiet that may be within their specifications or not.

They mentioned via email that 5% is within specs but:
1) it's actually 7%
2) if all 3 fans run at the same speed which is -7% vs nominal, either we are wiitnessing an act of God, or it's not just a measuring error.

 

[dolama72]

Reeporting back after having returned the 120mm and ordered 140mm version and installed it in the neew build.
New PC altogether, I only kept the SSD drives including the OS, which has not been reinstalled.

Guess what? Same story, the max RPMs are exactly 200 RPM less than the nominal max...

 

[solidsnake1298]

Keep in mind that, unless it is a high amperage fan connector (HAMP on Asus boards), motherboard fan connectors are typically limited to 1A at 12v (12W). And the manual for your board indicates it does not have a HAMP fan connector. Each of these fans at max speed draws 6w, half of the connector's power. The 2 case fans sharing a connector are maxing out that connector's output. For the fan on your AIO, you have to consider that it also has to deal with the back pressure from pushing air through the radiator. Even if the CPU fan connector isn't maxed out, the fan is maxed out and has a lot of extra resistance to deal with. 2800rpm is a reasonable speed considering the above.

Either way, what circumstance are you going to be running your fans that fast? Even "if it is only" 2800rpm? My case fans are set to stay between 40-60% PWM, 800-1200RPM for my Noctua iPPC 2000 fans (F12 and A14), and are nearly silent but the airflow is still sufficient to keep things cool. I suspect most people here have their fans around that same speed. You're spending a lot of time chasing 200rpm. And those 200rpm would not result in any measurable benefit.

Edit: Correction. 6w for 140mm, 3.6w for 120mm. My latter point still stands.

 

[dolama72]

Keep in mind that, unless it is a high amperage fan connector (HAMP on Asus boards), motherboard fan connectors are typically limited to 1A at 12v (12W). And the manual for your board indicates it does not have a HAMP fan connector. Each of these fans at max speed draws 6w, half of the connector's power. The 2 case fans sharing a connector are maxing out that connector's output. For the fan on your AIO, you have to consider that it also has to deal with the back pressure from pushing air through the radiator. Even if the CPU fan connector isn't maxed out, the fan is maxed out and has a lot of extra resistance to deal with. 2800rpm is a reasonable speed considering the above.

Either way, what circumstance are you going to be running your fans that fast? Even "if it is only" 2800rpm? My case fans are set to stay between 40-60% PWM, 800-1200RPM for my Noctua iPPC 2000 fans (F12 and A14), and are nearly silent but the airflow is still sufficient to keep things cool. I suspect most people here have their fans around that same speed. You're spending a lot of time chasing 200rpm. And those 200rpm would not result in any measurable benefit.

Edit: Correction. 6w for 140mm, 3.6w for 120mm. My latter point still stands.

I totally get it, I’ll never even want to use them at that speed. I was just trying to understand what the problem is and if it’s hiding something else.
Experience teaches that two big mistakes can partially cancel each other showing a minor one

 

[aigomorla]

id return them if you can, as bequiet is not a great fan vendor over someone like Noctua or Nidac which are priced the same.
But it could be the motor on the fan or some form of limiter.

Have you tried all fans to see if the issue is repeatable on all 3 fans you bought?

 

[solidsnake1298]

@aigomorla He is on his second set of fans, first 120mm and now 140mm (I missed the swap from 120 to 140 when I wrote my first post). Different motherboards, too (I also missed this fact). The only common factor is they are bequiet fans. IMO, not worth the hassle of returning and swapping to be able to run 3000 vs 2800rpm. But, if you do jump through those hoops, I second aigomorla's suggestion to go with a different manufacture. Noctua is my go-to. They also sell 3k RPM fans if you really need that much airflow.

 

[aigomorla]

Oh... then i think the vendor probably lied about specs, which is not uncommon.
If you really want that extra 200rpm, then i would switch vendor.
But like solidsnake states, its not really worth it, but noctua fans do have a better pressure curve, and so does Nidac Gentle Typhoons.

 

[dolama72]

@aigomorla He is on his second set of fans, first 120mm and now 140mm (I missed the swap from 120 to 140 when I wrote my first post). Different motherboards, too (I also missed this fact). The only common factor is they are bequiet fans. IMO, not worth the hassle of returning and swapping to be able to run 3000 vs 2800rpm. But, if you do jump through those hoops, I second aigomorla's suggestion to go with a different manufacture. Noctua is my go-to. They also sell 3k RPM fans if you really need that much airflow.

Thanks for the recap, it’s perfect.
I will stay with the be quiet. I mounted them with their case fan option with pins (not screws) and configured some curves with Fan Control.
The system is dead quiet and temperatures well under control.
I’m very satisfied.
The question was more if I had something wrong in my system (bios, OS) to read exactly 200RPM less in both situations. Which is still a mystery!
But I guess I will never find out.

I thought I found the issue when I found out that in my bios settings I had 200 RPM as minimum speed, but even after removing it nothing changed…

 

[solidsnake1298]

I thought I found the issue when I found out that in my bios settings I had 200 RPM as minimum speed, but even after removing it nothing changed…

That setting is supposed to detect when a fan is busted. Either not spinning at all or spinning waaay below the commanded speed. My lowest configured speed is 40% (800rpm on my 2k max rpm fans) and my minimum is set at 600rpm. I'm not actually sure how it alerts you if a fan dies and drops below that threshold. I'd imagine there is an alert while in the BIOS, but will it also pop-up an alert in your OS?