Pump RPM reading is 4200?

[Patishi]

Hi,
This is my first time installing AIO so this is probably a noob question.. but I set the pump header to run at 80% constant speed, and the pump RPM range (from the official specs) is 800-2800.
HWinfo shows ~4200 RPM. Is this normal behavior? and if it is fine I am interested to know why it works like that.
Thx.

 

[LeDoyen]

water pumps usually have a magnetic sensor to count RPM, with little magnets embedded in the impeller. For obvious balancing reasons there's two of them, so the speed signal reads two impulses per rotation.
So basically the real RPM is half what HWinfo shows. It reads the raw signal.

 

[Patishi]

water pumps usually have a magnetic sensor to count RPM, with little magnets embedded in the impeller. For obvious balancing reasons there's two of them, so the speed signal reads two impulses per rotation.
So basically the real RPM is half what HWinfo shows. It reads the raw signal.

Thank you very much for the explanation!