[SOLVED] Question about RADIATOR FANS not spinning faster while under load.

PaPies

Distinguished
Feb 5, 2014
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Hello, I have a question about the fans always being on the lowest setting set by the BIOS.

I want to give as much information as possible so I can get the best possible answer, so here it goes:


My motherboard doesn't have a dedicated AIO_PUMP connector, so at the beginning I connected the 3 way splitter of my ML 360R RGB to CPU_FAN and the pump to SYS_FAN1
I would notice that 3/4 times when I startup my computer, the fan wouldn't work and my temp would be at 99C for around 10 minutes before the system decides OH, I have a pump that I need to run.

So I swapped those around, pump into CPU_FAN and the 3 way splitter RGB into the SYS_FAN1 that also has the 3 radiator fans.

Since I fixed my first issue of the pump not working, there is another issue now that I am facing, and it's the fans not spinning up to match the charts in the bios that I've set, but even on default Normal or Silent Mode they don't spin any less or more, just take the first value dot and stick to it no matter what, this will cause my temps to slowly and linearly go up over time.

How can I fix this problem where the radiator fans would spin up when the CPU temp is reached to whatever it's set on BIOS?
 
Solution
OK, there's a good solution for this. Some background to help understand.

Your mobo has two fan control systems. Each operates the same way with a small difference. Each uses a temperature sensor for guidance, and alters the speed of its fans to ensure that the actual temperature at that sensor is on the pre-set target. IF you use the screens to change the settings of what temp to run for what temperature, that does not change the fundamental strategy. What is different between these two groups is only WHICH temperature senor it uses. The CPU_FAN header almost always gives you no choice on this matter - it always uses only the temperature sensor inside the CPU chip as it guide. All of the SYS_FAN headers normally use, instead, a...

Ralston18

Titan
Moderator
Update your post to include full system hardware specs and OS information.

Include PSU: make, model, wattage, age, condition,

Fans: numbers and configuration?

What are the configured temperature settings in BIOS? Or elsewhere if you changed any of the temperatures....
 

PaPies

Distinguished
Feb 5, 2014
172
6
18,685
Update your post to include full system hardware specs and OS information.

Include PSU: make, model, wattage, age, condition,

Fans: numbers and configuration?

What are the configured temperature settings in BIOS? Or elsewhere if you changed any of the temperatures....
MB: Z490 Gaming X
Cooling: ML 360R RGB Coolermaster
CPU: 10700K
GPU: RTX 3080 Gigabyte Eagle
PSU: V750 Fully Modular Cooler Master, 3 Years
OS: Windows 10.

FANS: 3 Pull fans on Front, 3 Push fans w/ radiator on top, 1 push fan fan at the back.
Bios configured temps on SYS_FAN1 (Where the radiator fans are connected to) are :
20C - 20%,
35C - 30%,
45C - 42%,
55C - 60%,
68C - 100%

The speeds will be locked at the 20% and never change when the temps go up. I've only used Bios to change the fans and I would prefer it stays that way unless I have no other choice
 

Paperdoc

Polypheme
Ambassador
OK, there's a good solution for this. Some background to help understand.

Your mobo has two fan control systems. Each operates the same way with a small difference. Each uses a temperature sensor for guidance, and alters the speed of its fans to ensure that the actual temperature at that sensor is on the pre-set target. IF you use the screens to change the settings of what temp to run for what temperature, that does not change the fundamental strategy. What is different between these two groups is only WHICH temperature senor it uses. The CPU_FAN header almost always gives you no choice on this matter - it always uses only the temperature sensor inside the CPU chip as it guide. All of the SYS_FAN headers normally use, instead, a different sensor on the mobo because they normally power fans used to cool the entire case interior.

Connecting the PUMP unit of your AIO system to the CPU_FAN header is the correct way. An important second function of that header is to monitor the SPEED signal from its "fan" (in this case, actually the pump speed for FAILURE. If that signal ever indicates NO speed, you will get a very prominent warning. On some mobos (don't know about yours for sure) such an event can even result in a complete shut-down of your system in a short time, without even waiting for the internal CPU temperature to rise a lot. With an AIO system, the most important component to monitor for failure is the PUMP, so it is best to connect that unit to the CPU_FAN header. However, there is one item you should adjust for that header's configuration - see p. 37 of your manual and ensure you are working on the CPU_FAN header. The wiring of the pump is using a small quirk of the designs of 3- and 4-pin fan systems so that the pump will always run full speed - that is what it is designed to do. For this two work, the header MUST be operating in the new PWM Mode. So look at the configuration options for that header, and set Fan Control Mode to PWM - not to Voltage and not to Auto. ALSO set Fan Stop to DISabled and Fan Fail Warning to ENabled if you have these options for this header.

Now, with your mobo's headers you need to power the rad fans and control them according to the temperature sensor INSIDE the CPU chip. Where you have them connected now probably is using the mobo temp sensor, and that is why they do not seem to track your CPU's activity level. You have four SYS_FAN headers available, and each of them CAN be set to use the sensor you Choose. So, disconnect those rad fans from the SYS_FAN header they are sharing with your case fans. Get a Splitter if you don't have one. Connect all of the RAD FANS to one SYS_FAN header and then, in BIOS Setup, configure that one header his way (see p. 37):
Fan Speed Control to Normal (automatic according to the speed-vs-temp curve)
Fan Control Use Temperature Input to CPU, not motherboard
Fan Control Mode to PWM for 4-pin fans (Voltage if they are 3-pin)
Fan Stop to DISabled - you never want those fans to stop
Temperature Warning Control to 80 C for now - if you get too many hot CPU warnings at very high workload, change this
Fan Fail Warning to ENabled

For the header you are still using for all your case ventilation fans, set
Fan Control Use Temperature Input to motherboard, not CPU
Temperature Warning Control to 60 C for now - if you get too many hot motherboard warnings at very high workload, change this

When you have all your fan headers configured, remember to use Esc to back out to the Main Menu, then F10 to get to the Exit Menu (p. 42). There choose Save and Exit to save these settings and reboot. with these settings you will get:
Pump will run full speed all the time, and mobo will monitor it for failure.
RAD FAN speeds will be adjusted automatically according to the temperature measured inside the CPU chip.
CASE FAN speeds will be adjusted automatically according to motherboard temperature.
 
Solution