Question PWM Fans seem to be really loud after change of PC-Case (incl. Fans) - can´t put them lower than 60 %?

[kev.med]

Hello everyone,

I have just finished installing the old setup of my girlfriend in her newly gifted PC-Case. Since the System was running before, it was pretty clear that everything should work fine after the rebuild. The Problem we are having now is that the Case-fans, which were included with the case seem to be pretty loud.
I have tried to reduce the speed in the BIOS and it went a little quiter. Nevertheless it is still running fairly loud.

I have looked up some articles online and found out, that pwm fans should be able to do pretty low speeds. On the manufacturer site the fans are said to be at 500 rpm at their lowest. The speeds that were the lowest, that i could achieve were from 725 to 1123.
It is a very old system, but i am still hoping, that i can get it a little more quite in idle.

System Stats:
Case: NZXT H5 Elite + 1 additional 120 mm fan (total of 1 x 120 mm pwm, 2 x 140 mm pwm, 1 x 120 mm dc)
Mainboard: ASUS ROG Rampage IV Elite
CPU: Intel i7-3930K
Ram: 32 GB DDR3
GPU: 2 x GTX 970 with SLi bridge
Power Supply: Enermax Triathlor ECO 800 W


Thanks in advance for any help and please ask I need to specify anything further.

 

[sonofjesse]

You can control your fan speeds in "bios", but if the room is 90F, then of course the fans will ramp up trying to cool off.

Remember too different cases have different thermals and acoustics.

 

[Paperdoc]

That mobo has three different groups of fans with slightly different means of adjusting. PLUS it has a permanently-installed fan called the PCH Fan that cools a couple mobo components, but you will NOT be using that for plugging in your own fans. However it will contribute to noise, depending how it operates.

The CPU_FAN and CPU_OPT headers are guided by temperatures measured by a sensor inside the CPU chip. They operate identically, so you configure both in one place - see manual p. 3-32. If you set the Profile item to Standard it uses a pre-set "fan curve" to decide what speed signal to send to its fans from the temperature measured. Silent and Turbo choices are just fixed speeds slow or very fast. Manual allows YOU to specify the fan curve used but this "curve" is a simple straight line between a low temp and a high temp point. YOU get to set each of these two points by setting the TEMP and Duty Cycle (as a % of full speed). Obviously ou cannot set the max speed over 100%m si any temps above the max temp you set will still generate max fan speed. At the low end, some mobos will treat the lowest speed % as the very minimum it will allow, so the fans will not go slower than this at even lower temps. NOT sure how your mobo does this. So, if you want to force your fan to run slower, use this Manual option and set the LOW TEMP to the lowest it might get (probably room temperature of 20 C when your system first starts up from "cold") and the min speed to something like 20%. Experiment with this min speed to find out how low it goes before the fan STALLS. Then set the min a bit higher that that so it NEVER stalls - MAYBE so it does not go lower than the 500 RPM spec.

The three CHA_FAN headers are guided by a different temperature sensor on the mobo. Each can be configured separately. The all have the SAME types of options as the CPU_FAN header, just using a different temp sensor for input.

The three OPT_FAN headers have different choices. Duty Cycle allows you to set a fixed fan speed %. Profile Mode allows you to choose from some pre-set fixed speeds. User Mode allows you to set your own 2-point "fan curve" again. However, in this case you do NOT get to set what the mon and max speeds are. You only get to specify the TEMPERATURES at which those speeds are used. The manual does not specify, but I suspect the temperature sensor uised here is that same mobo sensor that the CHA_FAN header use.

 

[kev.med]

Hello @Paperdoc,

Thank you very much for your detailed answer. I understood everything you wrote so far.
However i still have one or two questions that i´d love to have an answer for;

I was just checking the BIOS right now to make sure I don´t say anything wrong. What still confuses me is the following:

For The CPU Fan it works out just as you told me. I can put it down to basically 0 % at what temperatur i want.

The Mainproblem, that is still present are the chassis fans: I can only control all at once; Here i can select an upper Temp. and a max duty cylce. So far so good.
For the low temp. there is 40 degrees set, which i dont really mind. What I do mind, is that i can´t select any values lower than 60 % for the chassis fan min. duty cycle.
I feel like that is pretty high for the lowest setting.
Also the lowest setting for the optional fans with a fixed percentage is 50 % which i find rather high as well...

I also know that the current Bios is pretty outdated: Installed Version 1101; latest Version: 4901 (around 20-ish Versions in between)
Could this possibly fix the issue with the high percentage?

 

[Paperdoc]

I agree, those minimum settings seem pretty high. I certainly would expect you to be allowed to set lower. BEFORE you look at a BIOS Update I suggest you check this item. See the manual p. 3-33 (if you have it) under Chassis Fan Speed Low Limit. This is an item to set what limiting minimum speed of the fan that will cause a low-speed WARNING to pop up on your screen. It MAY be that the setting you are trying to make (Chassis Fan Minimum Duty Cycle) is restricted by the min speed alarm setting. So try lowering the alarm setting first.

ALSO recognize that you are allowed to change the upper and lower temps and duty cycle settings ONLY if you have chosen the use the MANUAL Profile setting.

Often, updating the BIOS it a good idea, particularly if you have problems as the system now operates. BUT there are some risks in doing this, because on occasion the update process causes errors in the data written to the BIOS memory and the updated version does not run! THERE ARE ways to prepare for this minor disaster - see the manual on p. 3-42. But heed the warning - it is better NOT to update if you really do not have a problem that needs fixing. In your case, IF you cannot lower those case fan speeds, is that problem big enough? If you do decide to update, I recommend NOT using the ASUS Update application that runs under Windows. I'd suggest the ASUS EZ Flash Utility (manual p. 3-46) which requires a USB memory stick that PREVIOUSLY has a new BIOS file copied to it BY YOU and CAN work with a BIOS that still is working well. It does NOT require that you have the CD of utilities that came with the mobo.

In the worst case when your BIOS is NOT working, see p. 3-48 for the procedures to use the ASUS BIOS Updater and a new BIOS file. Those TWO items are things you need to download and install on a USB drive BEFORE the disaster so you can use them. This process requires that the system be told to boot from the USB drive you have prepared ahead of time, AND it recommends you DISconnect all hard drives to avoid any confusion or potential for writing to the wrong place. Note also that it has an extra step for backup. The first step is to copy your CURRENT BIOS to the USB stick (so it needs enough space!); AFTER that you run it again to copy the NEW BIOS file you your mobo. IF for whatever reason that new BIOS does NOT work, you can repeat the process to restore the ORIGINAL BIOS to your mobo. People who are EXTRA leery of all this would use the first backup part of this two-step process before any other, so that you DO have a backup copy of the OLD BIOS that you can restore if necessary.

 

[kev.med]

Thank you for this detailed answer as well. Unfortunatly lowering the Chassis Fan speed low limit did not affect the lowest percentage.

Right now I am in contact with ASUS to see if they can help me...

 

[Paperdoc]

Very puzzling if you ARE using the MANUAL Profile setting. Let us know what ASUS can suggest.

Just another thought. Most mobos come with a CD of drivers and utilties, and often at intital set-up that installs a mobo makers's utility for easy access to mobo settings under Windows without going into BIOS Setup. In this case that would be Fan Xpert, part of their AI Suite II. IF that is installed and running, on every boot-up IT will take over and re-adjust mobo configuration settings to what Fan Xpert has been set to. So, is that installed?

 

[kev.med]

Haven´t been online for a year and I will just write this in case anybody else has some similiar problems with that specific board:

After talking with ASUS Support for a while they have told me the minimum fan speed you can set for this board seems to be 60%. So I have just given up on trying to get the fans to be more quite. I was thinking about getting a USB Fan-Controller where i would be able to set it lower but didn´t want to spend the money on it yet..

 

[Paperdoc]

Thanks for the update. I find it really odd that the mobo was designed that way, but apparently that IS the fact.