1 case fan spinning faster than rest

[ps3kirk]

I have a Phantek P400 temper glass and have 3 120mm Corsair Quite Fans installed on it, 2 in front panel and 1 in the back. My parts are:

Asus B-350 Strix motherboard
MSI GTX 1080
Ryzen 5 1600x
Coolmaster Hyper LED Cooler
Evga SC 3000 memory

My issue is that my lower fan on the front panel is going at 1600RPM while the other 2 are at 1135RPM. I switched the fan with another fan that came with the case but same problem persist. The case has room to breathe so i don’t think thats the issue.

In the BIOS all the fans take temp. from the CPU. Even with the case fully open it still runs at 1600RPM.

My temp fix is switching that fan to Motherboard temp. which makes it spin 100RPM less than the rest.

Any advice would be helpful.
Thanks

 

[CountMike]

Depends where it's plugged in.

 

[ps3kirk]

CHA2 on the motherboard which is 2nd case fan header. I got 3pin fan on 4pin header

 

[CountMike]

I don't know about tha BIOS but in mine has option to choose between Voltage control for 3 pin fans and PWM for 4 pin fans.

 

[R0GG]

From a lengthy experience with asus CrossHair formula V, running 4x120mm case fans + water cooler pump and it's fan: with the older Fan expert the adjustments of Fan speed curves under CPU FAN and Chassis Fan is very tricky, as the 3 Optional fan headers Fans have different behaviors than the ones hooked to regular Fan headers, also some Chassis fans follow CPU adjustments more than they would adapt to Chassis curve change. My mobo has 1 CPU FAN + CPU optional fan headers+ 3 Chassis Fans + 3 optional Fan headers, also Optional fans have baseline configuration in the bios ( not accessible in windows by fan expert software) which is separate from chassis fans baseline config. Your mobo probably has more configuration options in Bios and newer Fan Xpert software.
In order for me to get the 5 Fans around 800 to 1000 RPM each ( different brands and speed ratings : 2x Xigmatec 2000RPM (impossible to get these 2 to run at the same speed CH1 and CH3 but close enough), Corsair 2000, thermaltake 1600, Rosewill 1500, I had to go back and forth between Bios fixing fans baseline config.and windows Asus FanXpert adjusting CPU and Chassis Curves, a real pain in the neck. When Ramping up Fan curves when gaming the increase n speed is not proportional either but doesn't bother much.