[SOLVED] Pump Header on CPU_FAN or SYS_FAN ?

[LUCKASS]

Hello there, and sorry for my bad english!

EDIT: I saw here that it would be better to plug the pump onto the SYS_FAN, and run the pump at full speed for better flow and constant cooling : anyone could confirm ? If not so, I think I will plug both PUMP and Radiator Fan to CPU_FAN to be sure.

Today I built my first ITX config, and I have some questions about my AIO :

My mobo is a Gigabyte - Z390 I AORUS PRO WIFI and my AIO is a Cooler Master - MasterLiquid ML120R
I read 10 times all of the documentations, asked on discord and checked on forums, but I can't find any answers.

My mobo have 3 fans connector : 1x CPU_FAN and 2x SYS_FAN, my question is, what do I need to connect to CPU_FAN ?

-> The pump + the fan on the radiator (with a splitter) ?
-> Only the pump ?
-> Only the fan on the radiator ?

Some screenshot :

Spoiler: MOBO

Spoiler: AIO

btw, I have 4 fans, all Corsair LL120RGB, RGB pin's of those are connected to the Node Pro, and the RGB pin of the AIO is connected right onto the motherboard.

Thanks for your answers!

 

[Traditore]

Pump goes to CPU, fans go to SYS_FAN via hub (splitter)

 

[LUCKASS]

Pump goes to CPU, fans go to SYS_FAN via hub (splitter)

I just saw that post :

You can plug 3-pin connectors on a 4-pin header like this:

Note that your 4-pin fan is a PWM fan that requires a 4-pin PWM header for it to function as intended. The 4th pin provides the PWM signal to your fan which allows it to change speed while using full +12V provided by the PWM header.

On the other hand, your 3-pin pump (as well as 3-pin fans) functions as a DC pump/fan. Plugging this on a 3-pin DC header will allow such pump/fan to change speed by variable voltage supplied by the DC header.

If you plug a 3-pin pump/fan on a 4-pin PWM header, such pump/fan will run in full speed 24/7 due to the constant +12V the PWM header provides.

Some motherboards have 4-pin headers that are not true-PWM headers (the 4th pin is physically there, but has no electrical connection). You need to consult your motherboard's manual if such 4-pin header that you'll plug your 4-pin fan and your 3-pin pump/fan into is a PWM or a DC header.

Note that some motherboards have special features in the BIOS for you to select how such 4-pin headers function. You can choose the fan header to work either in PWM-mode (constant +12V with PWM signal) or in DC-mode (variable voltage with no 4th pin connection).

More often than not, it is recommended that AIO pumps should be run in constant speed to maintain constant liquid flow and to prevent the pump motor to experience more wear-and-tear if speed varies all the time.

Are you sure I have to put it on CPU_FAN ? Would it be better to have the pump at full speed, and plug it to SYS_FAN ?

Maybe raisonjohn should be able to answer..

 

[drivinfast247]

LUCKASS, thank you for providing your system specs and those pictures. That was a well laid out first post. I just had to say that.

 

[drea.drechsler]

The rule I've always used is an AIO pump should always operate at 100% so if the motherboard has a 'CPU Pump' header that isn't controllable I'll use that. Otherwise, to save a controllable fan header I plug the pump into a SATA power plug using an appropriate adapter.

Then I plug the radiator fan(s) into CPU Fan header or CPU Pump (if it has one and is controllable) and control speed on them against CPU temp.

Plug case fans into whatever fan headers are left with a bias towards controllable ones. Pay attention to match PWM fans and PWM controls as some don't work with voltage control fans or vice versa.

Never leave any CPU (anything) header open, though. Some motherboards won't start up unless it detects a CPU fan or pump that's working.

 

[Karadjgne]

Corsair and others put the pump on cpu_fan for only 1 reason. They expect the pump to fail before the fan. If the pump fails, it'll normally read 0rpm, at which point the cpu will shutdown the pc and refuse to boot.

Normal user hookup puts the fan on cpu_fan and the pump on cpu_aux/alt/pump or a sys header, just to maintain control of fan speeds according to cpu temp.

Either way works.

 

[LUCKASS]

The rule I've always used is an AIO pump should always operate at 100% so if the motherboard has a 'CPU Pump' header that isn't controllable I'll use that. Otherwise, to save a controllable fan header I plug the pump into a SATA power plug using an appropriate adapter.

Then I plug the radiator fan(s) into CPU Fan header or CPU Pump (if it has one and is controllable) and control speed on them against CPU temp.

Plug case fans into whatever fan headers are left with a bias towards controllable ones. Pay attention to match PWM fans and PWM controls as some don't work with voltage control fans or vice versa.

Never leave any CPU (anything) header open, though. Some motherboards won't start up unless it detects a CPU fan or pump that's working.

Corsair and others put the pump on cpu_fan for only 1 reason. They expect the pump to fail before the fan. If the pump fails, it'll normally read 0rpm, at which point the cpu will shutdown the pc and refuse to boot.

Normal user hookup puts the fan on cpu_fan and the pump on cpu_aux/alt/pump or a sys header, just to maintain control of fan speeds according to cpu temp.

Either way works.

Well, thanks you for your crystal clear answers !
I will choose to go for the fan on CPU_FAN for control !

Thanks again !