Radiator Fan speed issues

[gordopa1]

I recently built a new system and I am having an issue with the fan speed for the AIO fans. It is a Gigabyte AORUS B450 Elite mobo with a Fractal Celsius+ S28 AIO. I have the AIO hooked up according to the manual, with the pump (and thus fans) plugged in to the CPU_FAN header on the mobo. The fans for the AIO do not ramp up with temperature increases. If I use the Gigabyte SIV utility to set fans to full there is a definitive increase in sound and cooling performance, but any other setting seems to just keep the fans on their lowest RPM. I have tried setting Smart Fan 5 to Auto and PWM in BIOS and tried setting the pump between its Auto and PWM modes. What am I doing wrong?

[5x5]

Welcome to broken gigabyte firmware. Have you updated the BIOS and chipset drivers?

[gordopa1]

My BIOS is the newest and my chipset is up to date according to Gigabyte's available downloads, but not AMD's direct. Should I update to the most recent on amd.com?

[For Science!]

27 minutes ago, gordopa1 said:

 

It's not quite as simple, and you are getting confused as to how watercooling fan curves are usually set up. Since water has a high heat capacitiy, it takes much more energy for the internal water of an AIO to heat up than say, metal of a heat sink. Therefore, the cooling capacity is dictated by the fluid temperature, and there is no reason to increase fan speeds if the coolant is not heated. A correctly set up watercooling setup therefore will ramp up with watertemperature and not with CPU temperature, this prevents unnecessary ramping of fans with spikes in temperature and give a much better experience overall.

 

When the fans are plugged into the AIO, it is not simply acting as a passthrough to the CPU_FAN header, it is controlled by the firmware on the AIO itself. When put on Auto, the  behaviour should be as described above and is my recommendation. PWM moe on the otherhand is a passthrough mode that gives you "control" but do note that it still ramps up for the fluid temperature reaches unsafe levels.

 

In short you have done nothing wrong, this is just the way it is for liquid coolers, and the BIOS/motherboard have nothing to do with the particular non-issue you are seeing.

 

[gordopa1]

19 minutes ago, For Science! said:

It's not quite as simple, and you are getting confused as to how watercooling fan curves are usually set up. Since water has a high heat capacitiy, it takes much more energy for the internal water of an AIO to heat up than say, metal of a heat sink. Therefore, the cooling capacity is dictated by the fluid temperature, and there is no reason to increase fan speeds if the coolant is not heated. A correctly set up watercooling setup therefore will ramp up with watertemperature and not with CPU temperature, this prevents unnecessary ramping of fans with spikes in temperature and give a much better experience overall.

 

When the fans are plugged into the AIO, it is not simply acting as a passthrough to the CPU_FAN header, it is controlled by the firmware on the AIO itself. When put on Auto, the  behaviour should be as described above and is my recommendation. PWM moe on the otherhand is a passthrough mode that gives you "control" but do note that it still ramps up for the fluid temperature reaches unsafe levels.

 

In short you have done nothing wrong, this is just the way it is for liquid coolers, and the BIOS/motherboard have nothing to do with the particular non-issue you are seeing.

 

OK, I appreciate the insight. I'm seeing temps that I'm  not super comfortable with in this setup, so I may swap the factory thermal pad for some thermal compound to see if I can improve transfer from the IHS to the water loop.

[For Science!]

2 minutes ago, gordopa1 said:

OK, I appreciate the insight. I'm seeing temps that I'm  not super comfortable with in this setup, so I may swap the factory thermal pad for some thermal compound to see if I can improve transfer from the IHS to the water loop.

Consider also that the single biggest factor for CPU thermals is the CPU voltage, Ryzen2 in particular has some strange behavior that leads to high idle temperatures so keep that in mind too;