Guide: How to set up a fan curve in the BIOS

[pogoet154602d9]

Outstanding! Many thanks folks.

 

[SmokeyGrayPoupon]

citay,
Thank you for the informative and instructive fan curve guide. I completed my first build a few days ago (after 20+ years of owning pre-built machines) and your guide enabled me to reduce my air cooled cpu temps to a comfortable level as well as making my system virtually silent. I am very appreciative of the many knowledgeable posters in this forum.
Windows 11, MSI z790 Tomahawk DDR5 WiFi, I7 13700K, 32GB 5600, PSU 850, EVGA Nvidia 2060

 

[citay]

Thanks for the feedback, glad it could help you!

 

[pradeep_ro15a602e1]

Thanks for the feedback, glad it could help you!

Hello Sir...
Great writing on the fan control
I need your help...I recently bought a msi z490 motherboard online.
Since powering it on, the MOS fan is spinning close to 12k RPM.
After searching online, I figured it is a known problem with no clear solution in any of the forums other than RMA.
RMA is not an option for me since I bought it used.

Thanks

 

[citay]

Disable the VRM fan physically by unplugging/snipping the cable. In most cases, the fans are complete overkill. Those boards that use VRM/MOSFET fans, such as the Z490 ACE / GODLIKE, have an efficient VRM with Smart Powerstages, so there's no risk of overheating even with the fan disabled.

 

[SmokeyGrayPoupon]

citay,
I am planning to swap out my air cooler for a MSI Coreliquid s360 AIO. Would the same principles apply to a liquid cooled system as you have described in your fan curve guide?
Thanks for your instructive and informative input to these forums.

 

[citay]

Would the same principles apply to a liquid cooled system as you have described in your fan curve guide?

Yes, any water cooling leads to air cooling in the end (at the radiator). Whenever you have fans moving air to transport heat away, you apply similar principles as to what i described in the first post: Low revs when the temperature is low, slowly ramping up when it increases, and only in the high temperature range ramping up more rapidly.

With a liquid/water cooler, there's two additional things to consider: First, the pump, usually it goes onto the PUMP_FAN header, but how you control it depends on the specific cooler. Check the cooler manual on what they recommend. Sometimes it wants to be run at full speed all the time, sometimes it can be RPM-controlled with a fan curve depending on the thermal load.

Second, the airflow through the case, because apart from the CPU, there's other components that can generate considerable heat, primarily the GPU. So it's good if your CPU runs cool, but you also need to be aware of the other temperatures.

Thanks for your instructive and informative input to these forums.

Thanks for the feedback, always nice to hear.

 

[robman501154002d7]

Nice guide! Would it be possible to make the guide in to a document so I can print it off for myself?
Also, about my fans, I have 1 rear fan (SYS_FAN1), 2 top fans daisy chained (SYS_FAN5), and 3 front fans connected to the Corsair node plugged in to the USB header. Only thing I can do with the front fans is control the RGB lights. How can I have them spin down when the system is cool and ramp up when the system is warm?

 

[citay]

Would it be possible to make the guide in to a document so I can print it off for myself?

I mean, you can select all the text and pictures, copy it into your word processor, and see what it makes of it. I had to make a bunch of small little edits to keep a decent readability here on the forum, because sometimes the automatic line breaks can make sentences or paragraphs look awkward. Also, sometimes i edit the guide when i think i could explain something better in a different way. So then i'd have to redo the document as well each time. So i think it's best if you just copy it into Word or LibreOffice Writer or whatever, and see what happens.

3 front fans connected to the Corsair node plugged in to the USB header

It depends what this Corsair node is for. If it's only for RGB, then only the RGB cables of the fans will go into it, and the seperate cable each fan has to power the fan motor will go somewhere else. You have to check that, an RGB fan will always have two cables, one for RGB, one for the fan motor (either 3-pin / DC or 4-pin / PWM).

The B550 GAMING EDGE WIFI you seem to use has a whopping eight fan headers, so you could plug everything into the fan headers on the board and have full control.

 

[username]

Another excellent post that deserves to be "stickied" -
(now, you just need to post one for GPU fan curve management)

 

[robman501154002d7]

It depends what this Corsair node is for. If it's only for RGB, then only the RGB cables of the fans will go into it, and the seperate cable each fan has to power the fan motor will go somewhere else. You have to check that, an RGB fan will always have two cables, one for RGB, one for the fan motor (either 3-pin / DC or 4-pin / PWM).

The B550 GAMING EDGE WIFI you seem to use has a whopping eight fan headers, so you could plug everything into the fan headers on the board and have full control.

Okay, so for the RGB fans, the RGB cable would go on JRGB or JRAINBOW and the fan cable would go to the SYS_FAN header?
I'm not sure how I would do that. This is what the fans are connected to now.
The motor cable for the fans is connected to the Molex connector on the power supply. The RGB cable seems to be connected to the USB header.

 

[robman501154002d7]

(now, you just need to post one for GPU fan curve management)

"MSI Afterburner" might so that.

 

[citay]

The motor cable for the fans is connected to the Molex connector on the power supply. The RGB cable seems to be connected to the USB header.

Probably on a Molex-to-3/4pin adapter like this?

And the RGB controller is on a USB 2.0 header of the board, so the Corsair software can control the RGB effects, obviously.

What you do is, you take the fan's power cables off the Molex adapter and plug them into the free SYS_FAN headers individually, then you can control them all. You don't have to set different curves necessarily, but it's good to be able to control them individually if need be.

 

[robman501154002d7]

Probably on a Molex-to-3/4pin adapter like this?

And the RGB controller is on a USB 2.0 header of the board, so the Corsair software can control the RGB effects, obviously.

What you do is, you take the fan's power cables off the Molex adapter and plug them into the free SYS_FAN headers individually, then you can control them all. You don't have to set different curves necessarily, but it's good to be able to control them individually if need be.

That's the one! Mine just has one wire, not 4. Same idea though. If I connect the fans to the SYS_FAN headers, would I still be able to change the RGB effects of the fans or just the motor speed? The motherboard user guide just shows the RGB cable and the motor cable but the fans only have the one 4 pin cable.

 

[P.D&n]

Thanks citay. some user experience here from my side, the bios has a minimum fan speed. Probably to avoid long durration over current. I was looking to turn them off on low temp, but I don't think I can... My fans are 4 pinned and after setting it and take a peak after a week or so, it is back setted to DC. I can't explane...

 

[citay]

f I connect the fans to the SYS_FAN headers, would I still be able to change the RGB effects of the fans or just the motor speed?

You can control both, they are independent. Meaning, if you were to only connect the RGB cable and not the fan motor cable, then the RGBs would turn on and you could control the RGB effects, with the fans standing still. Or if you were to only connect the fan motor cable, then the fans would run, but without any lights. If you connect both (to the right places), you can control both.

Thanks citay. some user experience here from my side, the bios has a minimum fan speed. Probably to avoid long durration over current. I was looking to turn them off on low temp, but I don't think I can... My fans are 4 pinned and after setting it and take a peak after a week or so, it is back setted to DC. I can't explane...

No, the BIOS has no minimum fan speed, it's completely individual to the fan model you are using. There can be no overcurrent drawn from the fan running at very low RPM.

With 4-pin PWM-controlled fans, each fan model will interpret the PWM signal coming from the motherboard differently. Of course, a 100% signal will always mean full speed, but how they interpret anything below that is completely up to them. Here you see an fan (Arctic P12 PWM PST A-RGB 0dB) which has implemented a semi-passive mode, it stays off with any PWM signal below 5%:

Another example of such a fan is this Noiseblocker one, which has the following PWM signal to fan speed mapping depending on the variant:

Other fans may stay off below 20% PWM signal. And a lot of common fans may just map the entire PWM signal range to their safe lowest and highest speeds and never turn off this way.

Of course then you can try to forego PWM control and attempt to use DC control instead. A lot of fan motors need a certain initial voltage to start spinning, and if you stay below that, they will not spin. There's a small problem in that the voltage to turn on is greater than the threshold at which the fan will turn off again once it's already spinning. What i mean by that is, for example it may need 4.5V to reliably start spinning, but once it's going, it will only stop spinning below 3.5V or so. So it's difficult to set a reliable curve like this. The best thing to do is to use 4-pin PWM-controlled fan models which clearly state that they offer a semi-passive mode.

edit: I also added some of this information to the first post.

 

[P.D&n]

Thanns for letting me know. I anley draw 50% off from the maximum speed I can. Db is my first concern, dust is my second. I can block it, but I prefer not too.

I know how pwm works, have a whol switching box of it. But DC, doesn't see unpossible with me. Curious wath you have to say.

Kr
Dave

 

[robman501154002d7]

@citay I've played around with the fan settings in the BIOS and I was surprised to see that when I set SYS_FAN1 to 0%, the 3 front case fans stopped spinning. I thought SYS_FAN1 was the rear fan.

 

[tHeSiD]

Quick tip. I setup my custom curves for all the fans on the motherboard but then I also have Fan Control running on windows with almost similar curves, Fan control seems to override the bios curves. If you want to control them when in windows this is very useful. My system is still new and I wanted to check what happens to temps when and experiment with different fan speeds and see how the temperatures act. You can use this tool to finalize on the curves you want to set and set them in bios and stop using this if you want.

Fan headers are numbered, in most cases are numbers like a clock with one starting at top of board and so as you go clockwise around the board top will be one then two, three four and so on.

You can always find the SYS_FANx numbers in the manual.

 

[P.D&n]

@citay I've played around with the fan settings in the BIOS and I was surprised to see that when I set SYS_FAN1 to 0%, the 3 front case fans stopped spinning. I thought SYS_FAN1 was the rear fan.

Hmm, what mobo do you have? I have slide the curve in to the upper right corner and it was still spinning. But I dit the same thing as you, when I just setup my mobo for the first time. And then it did work. So what am I doing wrong. maybe you toke a fix point?