Question Does my MOBO H81-Plus Support Voltage Mode for Fans?

May 23, 2019
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I have 2 3 pin sp120 fans and 2 3 pin af120 fans which always run on 100%, and i want to turn their rpm down however i havent found a way. i looked online and found that a reason they might be being controlled already is due to my bios having PWM instead of voltage control turned on, so wanted to know if i could do this and if not what other options i have to get quieter fans that dont run on 100% all the time. buying new fans is an option aswell. JUST A LITTLE NOTE - i have tried mutliple different software and adjusting the rpm in bios and none changes it.
 

Paperdoc

Polypheme
Ambassador
First, how are your four fans connected? I am presuming that all four of these are used for case ventilation - that is, none of them is used on your CPU as its cooler. But your mobo has only ONE CHA_FAN header, so connecting four fans to that would require that you use a Splitter system for four fans. I ask because the easy way to connect four such fans in your system would be NOT to connect to the CHA_FAN header, but to connect them instead directly to a PSU power output. IF that's what you have, then your mobo has no way to control them at all.

Now, there IS a way to get control, even if you don't have them connected that way now. First, a "rule of thumb": virtually any mobo fan header can supply up to 1.0 A max total current to all fans connected to it, so you need to verify the max current draw spec for each fan. In your case, the specs are 0.13 to 0.18 A max per fan, so a total of about 0.6 A max - OK for connecting them all to a single header. To do that you need a Splitter, NOT a HUB. (A Hub is a different device and really can be used only with 4-pin fan systems.) A Splitter has one input "arm" ending in a female (with holes) fan connector to plug into the mobo CHA_FAN header, and two (or more) male (with pins) output connectors to plug in your fans. A HUB, on the other hand, has one additional type or "arm" that must plug into a SATA or 4-pin Molex power output from the PSU, and you do NOT want one of those. Few Splitters come with four outputs, but some do and you can create one easily. Also note that the Splitter can be either a 3-pin or 4-pin type because a 3-pin fan WILL plug into a 4-pin male connector and work if the header sends out the correct signals. So, you can get a Splitter like this that looks like a small printed circuit board, and you just have to secure it properly so it does not short out to something

https://www.newegg.com/black-en-lab...cm_re=fan_splitter-_-9SIACJF5528562-_-Product

Although that unit has one of its outputs labelled for the CPU, ignore that (see later).

As an alternative, you can buy three common 2-output Splitters like this (3-pin model here, but 4-pin one would also work))

https://www.newegg.com/p/N82E168124...ter&cm_re=fan_splitter-_-12-423-168-_-Product

Plug two of them into the outputs of the third to make a "stack" that converts one mobo header into four outputs for your fans.

In using Splitters you need to remember a little detail. Any mobo header can accept the speed signal sent back to it from ONE fan for counting and display; it also monitors that signal for fan failure. But it gets totally confused if fed more than one signal, so any decent Splitter will only send back one, and ignore the speed signal of the others. When you use Splitters, only ONE fan's signal will be displayed and monitored for failure, and all the others on that Splitter system ignored - you'll never "see" them. But that has NO impact on ability to control speeds. It only means that YOU should check all those fans from time to time to be sure they all are still working. In the case of the 4-output board model, the only output connection that does end back that fan's speed signal is the one marked "CPU", but when you use it for a group of case vent fans just ignore that label.

So, with a Splitter system and four fans connected together, plug the Splitter input arm into your mobo's CHA_FAN header. Now to configure that header in BIOS Setup. Go to this web page for your mobo


Click on "Support" at top right, then on "Manual & Document", and download the correct version - I got the English User's Manual

https://dlcdnets.asus.com/pub/ASUS/...27.456572294.1558709797-1856104645.1502368712

See p. 2-8. It says to push the "Del" key during the initial POST screen displays. I prefer to hold that "Del" key down until the opening screen of BIOS Setup appears - see p. 2-7. Use the F7 key to toggle between EZ Mode and Advanced Mode, and go to Advanced Mode (p. 2-8), then choose Monitor from the top menu bar. See p. 2-32 to -34. Set the CHA_FAN configuration to: Chassis Q-Fan Control to Enabled, Chassis Fan Profile to Standard, and if necessary Chassis Fan Low Speed Limit to a suitable value. (Default is 600 RPM, but your fans MAY be able to run slower at minimum before stalling.) Use the Esc key to return to the main menu, then choose the Exit button at top right. See p. 2-42. There Choose "Save Changes and Reset" to save your settings and reboot.

On p.1-16, item 6, the labels on the CHA_FAN header lead me to believe that that header can only use the older Voltage Control Mode which is necessary for control of 3-pin fans, so this configuration should put all four of your fans under automatic speed control based on the temperature sensor built into the mobo. To verify it's working, do this simple check. The normal process when you system first starts up is that all the fans start at full speed for a few seconds at most as the POST process proceeds. But then the system detects that it is cool and slows down the fans. So, open your case when the system is off. Push the front Power button and watch the fans carefully. If they all come on fast, then slow down after a few seconds, then your system IS controlling their speeds properly.
 
May 23, 2019
19
1
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First, how are your four fans connected? I am presuming that all four of these are used for case ventilation - that is, none of them is used on your CPU as its cooler. But your mobo has only ONE CHA_FAN header, so connecting four fans to that would require that you use a Splitter system for four fans. I ask because the easy way to connect four such fans in your system would be NOT to connect to the CHA_FAN header, but to connect them instead directly to a PSU power output. IF that's what you have, then your mobo has no way to control them at all.

Now, there IS a way to get control, even if you don't have them connected that way now. First, a "rule of thumb": virtually any mobo fan header can supply up to 1.0 A max total current to all fans connected to it, so you need to verify the max current draw spec for each fan. In your case, the specs are 0.13 to 0.18 A max per fan, so a total of about 0.6 A max - OK for connecting them all to a single header. To do that you need a Splitter, NOT a HUB. (A Hub is a different device and really can be used only with 4-pin fan systems.) A Splitter has one input "arm" ending in a female (with holes) fan connector to plug into the mobo CHA_FAN header, and two (or more) male (with pins) output connectors to plug in your fans. A HUB, on the other hand, has one additional type or "arm" that must plug into a SATA or 4-pin Molex power output from the PSU, and you do NOT want one of those. Few Splitters come with four outputs, but some do and you can create one easily. Also note that the Splitter can be either a 3-pin or 4-pin type because a 3-pin fan WILL plug into a 4-pin male connector and work if the header sends out the correct signals. So, you can get a Splitter like this that looks like a small printed circuit board, and you just have to secure it properly so it does not short out to something

https://www.newegg.com/black-en-labs-30cm-cable-splitters/p/1W7-0053-00001?Description=fan splitter&cm_re=fan_splitter--9SIACJF5528562--Product

Although that unit has one of its outputs labelled for the CPU, ignore that (see later).

As an alternative, you can buy three common 2-output Splitters like this (3-pin model here, but 4-pin one would also work))

https://www.newegg.com/p/N82E16812423168?Description=fan splitter&cm_re=fan_splitter--12-423-168--Product

Plug two of them into the outputs of the third to make a "stack" that converts one mobo header into four outputs for your fans.

In using Splitters you need to remember a little detail. Any mobo header can accept the speed signal sent back to it from ONE fan for counting and display; it also monitors that signal for fan failure. But it gets totally confused if fed more than one signal, so any decent Splitter will only send back one, and ignore the speed signal of the others. When you use Splitters, only ONE fan's signal will be displayed and monitored for failure, and all the others on that Splitter system ignored - you'll never "see" them. But that has NO impact on ability to control speeds. It only means that YOU should check all those fans from time to time to be sure they all are still working. In the case of the 4-output board model, the only output connection that does end back that fan's speed signal is the one marked "CPU", but when you use it for a group of case vent fans just ignore that label.

So, with a Splitter system and four fans connected together, plug the Splitter input arm into your mobo's CHA_FAN header. Now to configure that header in BIOS Setup. Go to this web page for your mobo


Click on "Support" at top right, then on "Manual & Document", and download the correct version - I got the English User's Manual

https://dlcdnets.asus.com/pub/ASUS/...27.456572294.1558709797-1856104645.1502368712

See p. 2-8. It says to push the "Del" key during the initial POST screen displays. I prefer to hold that "Del" key down until the opening screen of BIOS Setup appears - see p. 2-7. Use the F7 key to toggle between EZ Mode and Advanced Mode, and go to Advanced Mode (p. 2-8), then choose Monitor from the top menu bar. See p. 2-32 to -34. Set the CHA_FAN configuration to: Chassis Q-Fan Control to Enabled, Chassis Fan Profile to Standard, and if necessary Chassis Fan Low Speed Limit to a suitable value. (Default is 600 RPM, but your fans MAY be able to run slower at minimum before stalling.) Use the Esc key to return to the main menu, then choose the Exit button at top right. See p. 2-42. There Choose "Save Changes and Reset" to save your settings and reboot.

On p.1-16, item 6, the labels on the CHA_FAN header lead me to believe that that header can only use the older Voltage Control Mode which is necessary for control of 3-pin fans, so this configuration should put all four of your fans under automatic speed control based on the temperature sensor built into the mobo. To verify it's working, do this simple check. The normal process when you system first starts up is that all the fans start at full speed for a few seconds at most as the POST process proceeds. But then the system detects that it is cool and slows down the fans. So, open your case when the system is off. Push the front Power button and watch the fans carefully. If they all come on fast, then slow down after a few seconds, then your system IS controlling their speeds properly.
Thank you so much for this indepth response to my problem, upon reading this would i be right in saying that the first splitter you linked that has room for 1 cpu and 3 case fans i would be able to use with my four by just plugging a normal case fan into the cpu slot? also with my current setup i have two of the rear case fans connected to the CHA_FAN header and the other two fans connected through the case, which confuses me as from this i would have thought i already should be able to control the two rear fans due to them already being plugged in through a splitter however this is not the case. any idea's why i cant already control the two rear fans plugged in through a splitter to my CHA_FAN header? im also a little confused as on the Splitter Hub with 4 outputs in the description it says "full speed run for 3pin fans" which i thought means it cant be controlled with 3 pin fans and will run at 100% speed just like my current ones, which if this is the case i could purchase 4 new 120cm fans if you have any recommendations as these are very loud and did want red led or none led ones anyway. Lastly, sorry to be a pain but is there any chance the adapters you link you would be able to find them on UK amazon or UK Ebay? as this would make it alot easier for me to purchase. Thanks alot once again.
 
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Paperdoc

Polypheme
Ambassador
1. Yes, the 4-output circuit board Splitter CAN be used simply with four case fans. The only thing different about the one labelled "CPU" is that it is the only output that sends its fan's speed signal back to the host header. So you DO want to have one fan plugged in there. Just to help understand, the label is intended for a slightly different situation. If you are trying to connect several fans specifically to the CPU_FAN header because it its the only one on your mobo with PWM Mode of control (and this was the case in some older mobos) then it is important that the ONLY fan whose speed is sent back to the CPU_FAN header is the real CPU cooler. Your situation is NOT that, so the label is useless.

2. You have 2 fans connected to CHA_FAN, and two others "through the case". I'm not sure what that last part means. Maybe your case has its own fan speed button on it. Or maybe you mean those last two are just connected to a PSU output. Whichever, neither of those two can be controlled by anything the mobo does. That can make it difficult to determine whether or not the two that ARE plugged into the CHA_FAN header actually are being controlled. Why do you believe they are not? As a simple test, do that check I outlined at the end of my earlier post. That is: open the case, boot up and watch those two rear fans only carefully. They should start up at full speed right away, then slow down after a few seconds. If they do that, then the CHA_FAN header IS able to control the speed of those fans, and connecting the other two fans to that same header by using a larger Splitter will get them all under that same control.

3. That item in the description of the 4-output Splitter is not clear enough. What it is supposed to be saying is that IF you use this device to connect 3- and 4-pin fans to a mobo 4-pin header that is configured to use PWM Mode, then the 3-pin fans' speeds will NOT be controlled. That is not a property of the Splitter. That is because the PWM Mode cannot control the speed of 3-pin fans. BUT IF the header you use is configured to use Voltage Control Mode (aka DC Mode), then the 3-pin fans' speeds WILL be controlled that way. (As an aside, if you do that with a mix of 3- and 4-pin fans it will work for all of them, because the new 4-pin fan design CAN be controlled using the older Mode even if that is not quite ideal from a technical viewpoint.) In your case, you have only 3-pin fans and this will work IF that CHA_FAN header already is using only Voltage Control Mode. In BIOS Setup it does not appear to have any option to choose its control Mode. I think that it can use only Voltage Control even though it has 4 pins because the labels shown for its pins in the manual seem to indicate that. But that is why I suggest doing that careful observation of the rear fans already connected to it, to verify whether or not their speed does change right after starting up.

4. IF that start-up observation test says those fans never slow down, then I am wrong about what the CHA_FAN header does. In that case there is one special fan Hub you can get to solve the problem. It is a different design that uses the PWM signal from a 4-pin fan header and converts that system into the older Voltage Control Mode to get control of older 3-pin fans. That is a good solution when you have only a fan header using PWM Mode, and several 3-pin fans you need to control from that header. When doing it that way you do not need any Splitter because this device itself is a 6-output Hub. IF you need that item, let me know here and I can show you exactly which to get. The other option in that case, of course as you suggest, is replacing all four fans with 4-pin models.

5. Let me caution you because you spoke of "LED Fans". The first fans on the market with light in them were LED Fans. In them, the coloured lights mounted in the fan frame are LED's that are simply wired in parallel with the fan motor and are lit whenever the fan motor runs. But that mean the the max current consumed by that type of fan is typically 0.25 to 0.40 A each, significantly more than a plain fan. That becomes an issue when you want to connect four fans to a single header limited to 1.0 A max total current. So IF you do want to upgrade all your fans to LED fans, then a Hub probably will be needed to provide sufficient power. And then which Hub will depend on whether you are buying 3- or 4-pin LED fans, so post back here what you really plan to do. By the way, the more recent lighted fans are different. They are called RGB fans and come in two incompatible designs. But in them the lighting units are wired separate from the motors, so the concern about max motor load on the mobo fan headers does not need to include the LED power needs.

6. From Amazon.co.uk here is a circuit board Splitter with 4 outputs

https://www.amazon.co.uk/RDEXP-Plas...+fan+splitter&qid=1558728782&s=gateway&sr=8-6

And this is a package of four 4-pin Splitters with 2 outputs each, so you could create the "stack" I mentioned with 3 of them.

https://www.amazon.co.uk/Splitter-C...fan+splitter&qid=1558728951&s=gateway&sr=8-31
 
May 23, 2019
19
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1. Yes, the 4-output circuit board Splitter CAN be used simply with four case fans. The only thing different about the one labelled "CPU" is that it is the only output that sends its fan's speed signal back to the host header. So you DO want to have one fan plugged in there. Just to help understand, the label is intended for a slightly different situation. If you are trying to connect several fans specifically to the CPU_FAN header because it its the only one on your mobo with PWM Mode of control (and this was the case in some older mobos) then it is important that the ONLY fan whose speed is sent back to the CPU_FAN header is the real CPU cooler. Your situation is NOT that, so the label is useless.

2. You have 2 fans connected to CHA_FAN, and two others "through the case". I'm not sure what that last part means. Maybe your case has its own fan speed button on it. Or maybe you mean those last two are just connected to a PSU output. Whichever, neither of those two can be controlled by anything the mobo does. That can make it difficult to determine whether or not the two that ARE plugged into the CHA_FAN header actually are being controlled. Why do you believe they are not? As a simple test, do that check I outlined at the end of my earlier post. That is: open the case, boot up and watch those two rear fans only carefully. They should start up at full speed right away, then slow down after a few seconds. If they do that, then the CHA_FAN header IS able to control the speed of those fans, and connecting the other two fans to that same header by using a larger Splitter will get them all under that same control.

3. That item in the description of the 4-output Splitter is not clear enough. What it is supposed to be saying is that IF you use this device to connect 3- and 4-pin fans to a mobo 4-pin header that is configured to use PWM Mode, then the 3-pin fans' speeds will NOT be controlled. That is not a property of the Splitter. That is because the PWM Mode cannot control the speed of 3-pin fans. BUT IF the header you use is configured to use Voltage Control Mode (aka DC Mode), then the 3-pin fans' speeds WILL be controlled that way. (As an aside, if you do that with a mix of 3- and 4-pin fans it will work for all of them, because the new 4-pin fan design CAN be controlled using the older Mode even if that is not quite ideal from a technical viewpoint.) In your case, you have only 3-pin fans and this will work IF that CHA_FAN header already is using only Voltage Control Mode. In BIOS Setup it does not appear to have any option to choose its control Mode. I think that it can use only Voltage Control even though it has 4 pins because the labels shown for its pins in the manual seem to indicate that. But that is why I suggest doing that careful observation of the rear fans already connected to it, to verify whether or not their speed does change right after starting up.

4. IF that start-up observation test says those fans never slow down, then I am wrong about what the CHA_FAN header does. In that case there is one special fan Hub you can get to solve the problem. It is a different design that uses the PWM signal from a 4-pin fan header and converts that system into the older Voltage Control Mode to get control of older 3-pin fans. That is a good solution when you have only a fan header using PWM Mode, and several 3-pin fans you need to control from that header. When doing it that way you do not need any Splitter because this device itself is a 6-output Hub. IF you need that item, let me know here and I can show you exactly which to get. The other option in that case, of course as you suggest, is replacing all four fans with 4-pin models.

5. Let me caution you because you spoke of "LED Fans". The first fans on the market with light in them were LED Fans. In them, the coloured lights mounted in the fan frame are LED's that are simply wired in parallel with the fan motor and are lit whenever the fan motor runs. But that mean the the max current consumed by that type of fan is typically 0.25 to 0.40 A each, significantly more than a plain fan. That becomes an issue when you want to connect four fans to a single header limited to 1.0 A max total current. So IF you do want to upgrade all your fans to LED fans, then a Hub probably will be needed to provide sufficient power. And then which Hub will depend on whether you are buying 3- or 4-pin LED fans, so post back here what you really plan to do. By the way, the more recent lighted fans are different. They are called RGB fans and come in two incompatible designs. But in them the lighting units are wired separate from the motors, so the concern about max motor load on the mobo fan headers does not need to include the LED power needs.

6. From Amazon.co.uk here is a circuit board Splitter with 4 outputs

https://www.amazon.co.uk/RDEXP-Plas...+fan+splitter&qid=1558728782&s=gateway&sr=8-6

And this is a package of four 4-pin Splitters with 2 outputs each, so you could create the "stack" I mentioned with 3 of them.

https://www.amazon.co.uk/Splitter-C...fan+splitter&qid=1558728951&s=gateway&sr=8-31
Looked at my fans for you and they are 0.26A / 0.40A each, also did the test for fans however i could not see or hear them change in speed which really confuses me, so i repeated this about 3 times however same result. is there any chance i need to enable or disable something in my BIOS i havent? and would new fans be needed for this? if so any recommendations. Im pretty confused at the moment and have had this issue of loud fans since i got them, which has made me feel pretty annoyed for a while from this. my fans always seem to be about 1600 rpm which im pretty is there max and do not really ever go quieter, just sound somewhat like a jet engine. If pictures or PC specs are required let me know. also wanted to ask if this could be an issue due to an outdated bios as i have never updated the bios and is the same one that came with the Mobo the day i bought it.
 
May 23, 2019
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Okay upon even further inspection using CPUID HWMonitor to see my fan speeds (which i can only see for the one header, however this should represent 2) i watched the fans for about 3 minutes i saw them go from about 1200 rpm - 1600 rpm, so they are clearly being somewhat controlled however i am not able to control them at all and they are still extremely loud and shouldnt be on such a high rpm while the pc is just idle especially with my case having no obstructions like cables or bays in the way and also being pretty clean. (the case is NZXT S340) so im not quite sure what to think of all this and just want any options i could have for quieter fans. Thanks again.
 

Paperdoc

Polypheme
Ambassador
Let me ask for a specific detail. I understand you r arrangement currently is that TWO fans are connect to the CHA_FAN header using a simple Splitter, and two others are connected instead to a front panel source of some kind. As I said, I suspect those two at the front are under no control at all and will run full speed all the time. So if ALL your fans are running, sound alone will misinform you, because the noise of the two at the front will confuse your ears.

So try this to get it clear. Shut down and open your case. Find the wires for the two fans connected to the front and disconnect them. That leaves only the CPU cooler and the two rear fans on the CHA_FAN header connected. Now turn on and watch those rear fans carefully. Do they start fast and slow down in a few seconds? If so, the CHA_FAN header is able to change their speeds and thus must be using Voltage Control Mode..

Now, something else. Some third party fan monitoring tools give odd readings if they are not calibrated correctly. I don't know about HWMonitor. But look instead on the CD of software that came with your mobo. Also check its manual. There should be a utility on there that can be installed and run under Windows during normal operations (unlike the BIOS Setup screens) that allows you to observe the fans' settings and speeds, and make changes as you wish. In fact, you MAY already have it installed on your machine, but have not noticed it and never used it. This tool supplied by the mobo maker WILL give you correct fan speed readings. See what they tell you about two questions: (a) do the fan speeds on CHA_FAN actually change significantly (that is, more than +/- 20 RPM), and (b) what are the max and min speeds you observe? I agree that ranging from 1200 to 1600 is not a lot, so if those values are confirmed we may need to think further.
 
May 23, 2019
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Well I did some more looking around and it seems I made a mistake, the front two fans are the ones that I can actually control which must be the ones connected to the cha_fan header. I managed to use a software called speedfan to test this and did some tests disconnecting both sets to make sure it was in fact the two rear fans which are at 100% and the two front at auto, however the readings I gave from about 1250-1600 are still correct however for the front two fans. So I guess my next question is, in order to make them all auto how would I do this? As an adapter to the cha_fan header wouldn’t work due to being a total of over 1A (1.32), also there is still the problem with the pc being extremely loud, which I’m pretty sure is due to the fans only running at 1250-1600 rpm, which doesn’t seem to ever go lower. I get about 1250 rpm idle and 1400-1600 while gaming. I do kind of want new fans (four 120cm) which are not led and quiet so if u could link me some I would appreciate it. I also didn’t mention I only have a stock cooler on my cpu which I will try to upgrade soon to a hyper evo 212 at some point as I know the cpu fan makes quite a bit of noise however I tested and the case fans are over double. So to recap the problems are, 1. needing new fans so I can do the single cha_fan header splitter method. 2. My fans not going below 1250 even when idle with nothing open. 3. I’m quite confused why on speedfan, which is what a lot of pc owners use to manage their fan speeds use, you can change the output mode and it was on pwm by default, I then changed it to voltage mode and the fans went to max speed and auto fans speed stopped, so I went back to pwm output mode and it worked on auto 1250-1600 again, so I’m very confused why on voltage mode I wasn’t able to control the fans but on pwm mode I could, when I thought this would be the other way around. Thanks again.
 
May 23, 2019
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I also forgot to mention that a problem with the noise in itself I think is the types of fans I have as theses at 1600 rpm are 26 db, and with others I have seen before you can get as low as about 18 db still at 1600 rpm. So with this and the fact I want none led fans I would like to replace them which also means I then should be able to do four fans on one cha_fan header due to none led fans having a much lower power consumption.

In case you were wondering my specs I have a:
i7 4790k
Gtx 1060 6gb
H81-plus

And it seems that from monitoring my gpu fan speeds they don’t go lower than 1200 rpm either even when on 1% usage in task manager on idle. Which is odd as I thought they would turn off or go very low rpm when at only 40 degrees idle, however do not and although my gpu fan isn’t particularly loud it still is odd that this is happening.
 

Paperdoc

Polypheme
Ambassador
For a non-LED fan I like the Noctua line. They make a lot of models, so you need to get the exact model number right. Their fans have a reputation for good airflow at lower noise and they last a long time - longer than their 6 year warranty. A summary of their lines is here.

https://noctua.at/en/products/fan

From that, and using Amazon in the UK as a price reference, I suggest either of these two would suit you.

https://www.amazon.co.uk/Noctua-NF-...a+NF-S12A+PWM&qid=1558925780&s=gateway&sr=8-3

That is the Noctua NF-S12A PWM, a 4-pin 120 mm fan able to deliver 107 m³/hr using 0.12 A max current and generating noise up to 18 dBA (reasonably quiet). Comes in a two-tone brown colour.

https://www.amazon.co.uk/Noctua-NF-...NF-S12B+redux&qid=1558926456&s=gateway&sr=8-3

That is the Noctua NF-S12B redux-1200 PWM with very similar ratings but lower current consumption and at a lower price, in grey colour.

Elsewhere in that large listing you will also see models with higher airflow and backpressure ratings, but they run faster and generate noise in the 26 dBA range. That is still reasonably quiet, but if you really want low noise and do not need extra airflow, the ones I linked above might suit better. In the opposite direction they have Low-Noise models but those are designed to run much slower and deliver much reduced airflow.

A small note of caution. Noctua usually includes with these vans a small device called a Low Noise Adapter that you can insert into the fan's connection wires. This is just a resistor that drops the fan supply voltage so it runs slower and quieter, but also delivers substantially LESS air flow. It is very useful IF you have to connect your fan to a fixed 12 VDC power supply from the PSU but want lower noise and airflow. But if you are using your fan under automatic temperature control by a mobo header, do NOT use this LNA. Its main effect in that case is to prevent you from getting really good cooling when you need it at high workloads.

With the low current max ratings, you could use four of these fans easily with a splitter system from a single CHA_FAN header.

I linked to 4-pin PWM fans because you say you have found that your CHA_FAN header actually does control fan speeds when used in PWM Mode. That makes no sense to me if the fans you have are of the 3-pin type. BUT, no matter whether your CHA_FAN header can use PWM Mode or Voltage Control Mode (and your mobo manual does NOT say that option choice is available), a 4-pin fan's speed CAN be controlled by either Mode so it will work for you.
 
May 23, 2019
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Thank you for the informative and swift reply.
Personally I have been looking at “be quiet!” Fans as these are very well known for being quiet and mostly are just black which is what I want for my setup (also I wouldn’t really like to spend over 10 pounds due to me needing to replace all 4 and a cpu fan) Do you have any fans from this brand or noctua which would match a plain black colour theme? And finally I am still very confused on why although I’m able to control my two front fans manually, when I put them onto auto the rpm of them will never go below 1200 even though this speed is not needed, which I tested by using manual and finding at even about 600 rpm the fans are fine with the temperature being stable and not rising at all.

Here is a link to a model of fan I have in mind, and would like to know your thoughts? : https://www.amazon.co.uk/Be-Quiet-B...8978709&s=gateway&sprefix=be+quiet+fan&sr=8-6

Please let me know your opinions on all this. Thanks again
 
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Paperdoc

Polypheme
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The fan you linked to, the beQuiet Pure Wings 2 120mm PWM model (£9.33 on Amazon .co.uk, their lowest-priced beQuiet model) can do 87 m³/hr air flow at max speed generating 20 dBA noise, no spec for max current on the web page. An alternative from beQuiet is their Silent Wings 3 120mm PWM model (£16 on Amazon); it does slightly less airflow (80 m³/hr) at 16 dBA noise and able to work against slightly higher backpressure, still no current spec. Those airflows are 20% lower than the Noctuas I suggested above.

In the Noctua line, the all-black colour can be obtained with their model NF-S12A PWM Chromax Black Swap, but I see on Amazon it's £20.

An alternative is the Arctic P12 PWM model (£10.78 on Amazon .co.uk) which can be ordered in the Black / Black version, but be CAREFUL to order that specific colour variation. It is a 120mm PWM model optimized for higher backpressure (not really needed for your use) but able to deliver 96 m³/hr air flow with noise spec'd in a different type of measurement that ROUGHLY compares to about 20 dBA. It consumes 0.08 A, so no problem for four on one header. (The beQuiet fans did not spec their max current.) So compared to the beQuiet Pure Wings 2model, this can do slightly more air flow but costs slightly more.

https://www.amazon.co.uk/Arctic-P12-PWM-PST-Pressure-optimised/dp/B07GB5JRTZ/ref=dp_ob_title_ce?th=1

With a fair amount of searching those are the best options I could find that meet your desires for air flow, noise, cost, max current consumption and black colour in a PWM design 120 mm fan.
 
May 23, 2019
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Okay thanks for this. So am I right in thinking the only issue with the fans I wanted to get is it doesn’t state their max current? Also do you have any clue why my fans on auto won’t go below 1200 rpm? Even tho they go from 1200-1600
 

Paperdoc

Polypheme
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Yes, that's the only missing piece of info. It is needed only to verify that the total max current for four such fans on a single header using a Splitter does not exceed the header limit of 1.0 A.

Why they will not go under 1200 RPM is a puzzle. Here are some ideas to check.

  1. Use the fan observation tools provided by your mobo - either in BIOS Setup, or using the Windows monitoring app that comes on the mobo's CD - to verify the speed readings you get are correct.
  2. Use BIOS Setup to verify and adjust, if necessary, the CHA_FAN header configuration (manual p. 2-34, item 2.7.5.). It should be Enabled. Check the setting for Speed Low Limit and set that to 600 or lower - not too low so that the fan stalls. Set the Profile to "Standard". When done, click on "Exit" at top right to get to the Exit menu (p. 2-42). There choose Save Changes and Reset. I don't know where you find the "auto" setting, but I suspect it is in HWMonitor or Speedfan, and those tools may NOT be able to make the adjustments you require.
 
May 23, 2019
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Okay, well I went on the official bequiet website and found the exact same model fan that I wanted. It says there that the “current consumption” is 0.09 A and the “safety current” is 0.2 A so with this info doesn’t that mean they are 0.2A each? And I would be okay using splitters to have four on my cha_fan header? As this would be 0.8 A which would give me a little bit of headroom?
 

Paperdoc

Polypheme
Ambassador
You are right, and the situation is even better than that. "Safety current" is a maximum upper limit, and such a current flow might be sustained over a second or so, not more. Even though the mobo header's spec is 1.0 A max, it can deal with higher for a VERY short time. So for most purposes, the 0.09 A "consumption" number is what you need to consider.