If you are seeing an inconsistent fan speed reported from the fans included with your Kraken Core cooler, this article will address what is happening and what needs to be done.

What is happening?

Some early units of the Kraken Core RGB may show inconsistent (i.e. "jumpy") RPM readings in the UEFI/BIOS or via monitoring software (i.e. NZXT CAM, HW Monitor, etc.).  This is purely a reporting issue with the tachometer (TACH) sensor, the fans themselves are running at a consistent RPM and are cooling properly.  While it is normal for RPM readings to vary slightly (approx. ±10% at maximum speed), this reporting quirk makes the reported RPM look much jumpier than they really are.

Our Testing

To verify the consistent RPM, our team has tested the included F-Series RGB Core (EV-B) fans included with the Kraken Core RGB coolers via an optical tachometer.  This tool measures rotations per minute using a no-contact optical sensor.  The readings for the tachometer are directly compared to software readings.  With the fans set to 25%, 50%, 70%, and 100% the tachometer confirmed steady operation, while BIOS/software readings appeared inconsistent.

Warning - Testing video includes repeating sounds which may be unpleasant to some viewers.

25% Fan Speed

50% Fan Speed

75% Fan Speed

100% Fan Speed

What's changing?

Future production runs of the Kraken Core will include updated F-Series RGB Core (EV-B) fans with an updated control method that will provide a steadier RPM signal to software.  Cooling performance will remain unchanged, the change only affects how readings appear to software and UEFI/BIOS.

What do I need to do?

If you are seeing this behavior, there is no need to replace or adjust your cooler as the Kraken Core is working as intended.  There is no need to replace the fan so long as it is within 10% of the set performance (i.e. 2400 ±250 RPM @ 100%).  If you'd like more details or extra assurance, please reach out to our Customer Support team.