Need help adjusting fan control

[lansing]

I have a Fractal Design Celsius S36 AIO water cooler on a MSI x570 A-Pro motherboard. The water cooler came with a pwm/auto switch on the pump and MSI BIOS has a setting to control the fan.

 

I followed Fractal's setup guide and connect the radiator fans to the pump making it a single fan connector, and then I plugged it into the "pump fan" on the motherboard. I also have three 120mm case fans connected to the "cpu fan" on the board.

 

In the BIOS, I turn on the "smart fan mode" to overwrite the pump switch (I'm not sure). Now here's the problem, while the "pump fan" control curve successfully controlled on the radiator fans, the "cpu fan" curve does nothing to my three case fans. It is showing that the fans are running at 1900rpm the whole time, but when I put my hand around them, it feels like they're running at 500rpm.

[Bombastinator]

If the case fans are plugged into the CPU fan header what is plugged into the case fan header(s)?

[lansing]

4 minutes ago, Bombastinator said:

If the case fans are plugged into the CPU fan header what is plugged into the case fan header(s)?

I don't have any other fans. There're four "system fan" header on the bottom of the board, I just use the pump and cpu one.

[For Science!]

1 hour ago, lansing said:

 

The BIOS is reporting the pump rpm, which should be set at max speed (12 V constant, DC mode) for AIO pumps. The fan speed is controlled by the AIO itself reacting to (probably) fluid temperatures and so the BIOS will not show the fan speed, but this is intentional and should be left this way.

[Bombastinator]

1 hour ago, lansing said:

I don't have any other fans. There're four "system fan" header on the bottom of the board, I just use the pump and cpu one.

So zero case fans?

 

my thought is if you do have case fans, plugging them into the cpu header instead of just case fan header(s)  May be creating weird an unnecessary problems like the one you describe.  I think.

[lansing]

3 minutes ago, Bombastinator said:

So zero case fans?

The three cases are connected together into one header

36 minutes ago, For Science! said:

The BIOS is reporting the pump rpm, which should be set at max speed (12 V constant, DC mode) for AIO pumps. The fan speed is controlled by the AIO itself reacting to (probably) fluid temperatures and so the BIOS will not show the fan speed, but this is intentional and should be left this way.

So I opened the case and switched up the header. Now the three case fans are connected to the system fan header and it's showing up correctly in the bios.

 

So now should I be connecting the AIO pump to the pump_fan header and then in the bios choose DC mode and turn off the smart fan control?

[For Science!]

5 minutes ago, lansing said:

 

By case fans I assume you mean radiator fans. You've now unoptimized the liquid cooling setup since the BIOS has no idea of the fluid temperatures and ramp up the fans according to the CPU temperature by default. This is stupid with liquid coolers since you don't need to increase fan rpm unless if the coolant temperature increases. 

 

If you were to do this sensibly, taking the functionality of the S36 into account, you would:

 

1. Plug all radiator fans into the fan hub on the S36

2. Plug in the pump fan header into the CPU_FAN header

3. Set CPU_FAN header to be 12 V DC, Full speed mode, whatever in the BIOS that gives a constant 12 V to the pump

 

You're exchanging a lot of functionality for just being able to see the fan rpm in BIOS which in my opinion is super dumb.

[Bombastinator]

3 minutes ago, For Science! said:

By case fans I assume you mean radiator fans. You've now unoptimized the liquid cooling setup since the BIOS has no idea of the fluid temperatures and ramp up the fans according to the CPU temperature by default. This is stupid with liquid coolers since you don't need to increase fan rpm unless if the coolant temperature increases. 

 

If you were to do this sensibly, taking the functionality of the S36 into account, you would:

 

1. Plug all radiator fans into the fan hub on the S36

2. Plug in the pump fan header into the CPU_FAN header

3. Set CPU_FAN header to be 12 V DC, Full speed mode, whatever in the BIOS that gives a constant 12 V to the pump

 

You're exchanging a lot of functionality for just being able to see the fan rpm in BIOS which in my opinion is super dumb.

Argh.  They were radiator fans? Radiator fans are not case fans.  We need data.  Or maybe just I do.

@lansing

these fans of which you speak: are they or are they not attached to your radiator?

[lansing]

22 minutes ago, Bombastinator said:

Argh.  They were radiator fans? Radiator fans are not case fans.  We need data.  Or maybe just I do.

@lansing

these fans of which you speak: are they or are they not attached to your radiator?

The S36 has three radiator fans and I have connected them to the radiator hub already. I have another three 120mm case fans

[lansing]

44 minutes ago, For Science! said:

By case fans I assume you mean radiator fans. You've now unoptimized the liquid cooling setup since the BIOS has no idea of the fluid temperatures and ramp up the fans according to the CPU temperature by default. This is stupid with liquid coolers since you don't need to increase fan rpm unless if the coolant temperature increases. 

 

If you were to do this sensibly, taking the functionality of the S36 into account, you would:

 

1. Plug all radiator fans into the fan hub on the S36

2. Plug in the pump fan header into the CPU_FAN header

3. Set CPU_FAN header to be 12 V DC, Full speed mode, whatever in the BIOS that gives a constant 12 V to the pump

 

You're exchanging a lot of functionality for just being able to see the fan rpm in BIOS which in my opinion is super dumb.

Hi this is what I got so far, switching to DC mode did actually gives me the correct rpm, though I still don't know what number to put for the curve. Right now it idles at 43C, where it was 32C with the PWN mode.

 

[Bombastinator]

31 minutes ago, lansing said:

The S36 has three radiator fans and I have connected them to the radiator hub already. I have another three 120mm case fans

Ohgood.  that’s out of the way then.  No confusion.  3 case fans pointing in one triple radiator pointing out then I assume.  3xcase fan > 3xradiator fan because the radiator makes less airflow so mild overpressure case.  Make sure there’s filters for the case fans and it will even be dust free for years.

 

It is arguable that some fans have a PWN mode. 
 

[lansing]

Update, I think I fixed it, I turned the switch on the pump to "auto", and then in the bios I changed the fan control to DC mode and turned off the "smart fan mode", now the fan is reading a constant 1900rpm and auto adjusting itself.

 

Thanks all for the help.