Question Fan speed pulsing

[Counteracting]

I just recently upgraded my computer and the specs are as follows:

Motherboard: MSI B450 gaming pro carbon ac
Processor: Ryzen 7 3700x
Cooler: Cooler Master masterliquid ML120L RGB
Ram: G.Skill 32gb (2x16) 3600mhz
GPU: Gigabyte GTX 1080 OC
PSU: Corsair 750CX

At first all my fans were running full blast so I went into bios and turned smart fan control off, that fixed that issue but introduced another. My CPU fans keep pulsing, rapidly jumping from 1000 rpm to 1500rpm for no reason. I tried going back into bios and changing some stuff but nothing worked.

Any help is appreciated!

 

[Darkbreeze]

What are the EXACT models of your fans? Are all fans doing this, including the CPU cooler fan, or just the case fans?

Where are ALL fans connected to? Where are ALL fans installed, to what locations?

 

[Counteracting]

What are the EXACT models of your fans? Are all fans doing this, including the CPU cooler fan, or just the case fans?

Where are ALL fans connected to? Where are ALL fans installed, to what locations?

http://prntscr.com/qmalzg
Red = PUMP_FAN1
Green = CPU_FAN

Looking at this I think that it may be the wrong way around, please confirm it!

 

[EndEffeKt_24]

Your fans are set to ramp up as cpu temp increases. The "problem" is that the short boosts of PBO on Ryzen 3000 chips causes temperature spikes.
Since you got an aio I would try to control my fans via water temperature.

 

[Counteracting]

Your fans are set to ramp up as cpu temp increases. The "problem" is that the short boosts of PBO on Ryzen 3000 chips causes temperature spikes.
Since you got an aio I would try to control my fans via water temperature.

These are the option I have for my pump and cpu fan, im not sure what temperature source i should set for each one

http://prntscr.com/qmdk33

http://prntscr.com/qmdk8x

 

[Darkbreeze]

http://prntscr.com/qmalzg
Red = PUMP_FAN1
Green = CPU_FAN

Looking at this I think that it may be the wrong way around, please confirm it!

Are you telling me that the CPU cooler fan on your radiator is the ONLY fan you have installed in this system? Because if not, then your answer did not address any part of the questions I posed.

 

[Counteracting]

Are you telling me that the CPU cooler fan on your radiator is the ONLY fan you have installed in this system? Because if not, then your answer did not address any part of the questions I posed.

I have 2 other fans, one is above the motherboard, and the other one is under the radiator. Both connected to SYS_FAN headers on my motherboard. Only the CPU fan has the issue

 

[EndEffeKt_24]

These are the option I have for my pump and cpu fan, im not sure what temperature source i should set for each one

http://prntscr.com/qmdk33

http://prntscr.com/qmdk8x

Seems like you got no temp sensor. Thats a shame. In that case I would set the pump to a constant speed like 70%. For the fans I would increase the ramp up and down time. Maybe you got an option like hysteresis. You want to get rid of that constant up and down of the fans.

 

[Counteracting]

Seems like you got no temp sensor. Thats a shame. In that case I would set the pump to a constant speed like 70%. For the fans I would increase the ramp up and down time. Maybe you got an option like hysteresis. You want to get rid of that constant up and down of the fans.

I tried what you said and there is no difference, not sure what else to do. My friends are saying that its an issue with the motherboard

 

[Darkbreeze]

Ok, ok. Stop. Just stop.

So you have two case fans, and then you have the AIO radiator with one fan on it. Is that correct?

Forget about the "no thermal sensor" comment, that's just nonsense and shows that somebody lacks the experience here that should be present to even be commenting on threads like this.

The B450 Pro carbon of course has thermal diodes for fan and temperature controls.

I will tell you right now though, straight up, that the CM ML120 is far too small to handle the 3700x without difficulty. You need a bigger cooler. 240mm AIO should be the MINIMUM for that CPU. Especially if you expect to run PBO.

Even so, you should still be able to get the system to run without any kind of "pulsing" of the fans.

So again I will ask you, WHICH fans are pulsing?

Is it ALL of them. Or is it ONLY the radiator fan that is pulsing? All fans, when properly connected and configured to the proper thermal diode, will have variable speed control if the header they are connected to is capable of it AND if the controls are set to the right type. Right type being either DC or PWM.

Are your two additional case fans the type that have three wires or four?

Please take a few more pictures. I need a better picture of the fan on your radiator, preferably a little bit more straight on to the fan rather than at such an angle. Also, pictures of the other two fans as well.

Looking at your earlier picture it looks like you have the fan mounted incorrectly so that it is blowing OUT of the case through the front mounted radiator, and that is 500% wrong if that is how it is.

Let's start, before we go getting carried away trying to figure out a bunch of other crap, by making sure we even have the fans that are installed, installed correctly, before going any further.

 

[Counteracting]

Ok, ok. Stop. Just stop.

So you have two case fans, and then you have the AIO radiator with one fan on it. Is that correct?

Forget about the "no thermal sensor" comment, that's just nonsense and shows that somebody lacks the experience here that should be present to even be commenting on threads like this.

The B450 Pro carbon of course has thermal diodes for fan and temperature controls.

I will tell you right now though, straight up, that the CM ML120 is far too small to handle the 3700x without difficulty. You need a bigger cooler. 240mm AIO should be the MINIMUM for that CPU. Especially if you expect to run PBO.

Even so, you should still be able to get the system to run without any kind of "pulsing" of the fans.

So again I will ask you, WHICH fans are pulsing?

Is it ALL of them. Or is it ONLY the radiator fan that is pulsing? All fans, when properly connected and configured to the proper thermal diode, will have variable speed control if the header they are connected to is capable of it AND if the controls are set to the right type. Right type being either DC or PWM.

Are your two additional case fans the type that have three wires or four?

Please take a few more pictures. I need a better picture of the fan on your radiator, preferably a little bit more straight on to the fan rather than at such an angle. Also, pictures of the other two fans as well.

Looking at your earlier picture it looks like you have the fan mounted incorrectly so that it is blowing OUT of the case through the front mounted radiator, and that is 500% wrong if that is how it is.

Let's start, before we go getting carried away trying to figure out a bunch of other crap, by making sure we even have the fans that are installed, installed correctly, before going any further.

So you have two case fans, and then you have the AIO radiator with one fan on it. Is that correct?
I have 3 case fans, 2 of them are the stock NZXT fans, and one of them is a cheap 10$ fan (blue), then I have the radiator fan. 4 fans in total in the PC

http://prntscr.com/qmj2gj

http://prntscr.com/qmj2l8

http://prntscr.com/qmj2ms

So again I will ask you, WHICH fans are pulsing?
Only the Radiator fan is pulsing -- I've made sure of it

Is it ALL of them. Or is it ONLY the radiator fan that is pulsing? All fans, when properly connected and configured to the proper thermal diode, will have variable speed control if the header they are connected to is capable of it AND if the controls are set to the right type. Right type being either DC or PWM.
Only the radiator fan, DC and PWM are available for selection in bios

Are your two additional case fans the type that have three wires or four?
The NZXT fans are not connected to my motherboard, the radiator fan has 4 wires, the blue fan has 3 wires and the pump also has 3 wires

Please take a few more pictures. I need a better picture of the fan on your radiator, preferably a little bit more straight on to the fan rather than at such an angle. Also, pictures of the other two fans as well.
other fans above

http://prntscr.com/qmj3t4

http://prntscr.com/qmj3v6

Looking at your earlier picture it looks like you have the fan mounted incorrectly so that it is blowing OUT of the case through the front-mounted radiator, and that is 500% wrong if that is how it is.
You were right, It was installed wrong it is now blowing to the inside of the case. I switched it around but the issue still persists.

 

[Darkbreeze]

Ok, so radiator fan is now correct and is actually PULLING air in through the radiator. That is acceptable, although, typically we'd rather see the radiator fan PUSHING through the radiator OR even a push pull configuration on the radiator but that requires the use of specifically configured fans so that you don't instead create a problem of restriction or dramatically increased static pressure if one fan is not spec'd properly.

So anyhow, should be fine if you have it pulling outside air through the radiator.

Next, EXACTLY WHICH fan header is the radiator fan connected to and exactly which fan header is the pump connected to?

 

[Counteracting]

The radiator fan is connected to

Ok, so radiator fan is now correct and is actually PULLING air in through the radiator. That is acceptable, although, typically we'd rather see the radiator fan PUSHING through the radiator OR even a push pull configuration on the radiator but that requires the use of specifically configured fans so that you don't instead create a problem of restriction or dramatically increased static pressure if one fan is not spec'd properly.

So anyhow, should be fine if you have it pulling outside air through the radiator.

Next, EXACTLY WHICH fan header is the radiator fan connected to and exactly which fan header is the pump connected to?

Radiator fan = PUMP_FAN1
Pump = CPU_FAN

 

[Darkbreeze]

So, I'd go into the BIOS and make sure that the Pump fan header is set to DC if it is a 3 wire fan or PWM if it is a 4 wire PWM fan, and that you assign both a desired fan curve profile AND set the source to either CPU or water temp if those are options.

Then I'd set the CPU FAN header to DC or PWM based on how many wires are coming from the pump and set it to 100% at all times. No PWM or variable curve. Pump should be full speed, at all times.