CF631/SCAB Fan Control


New member
I recently purchased a 631 with SCAB and am using it to control 5 120mm fans. 2 of the fans came with my Silverstone TJ09 case, the other 3 are Scythe S-Flex SFF21F. 2 of the Scythe fans are on a Y cable connected to 1 SCAB port. The fan RPM divider in CC2 is set at 1, which shows my fans at around 1600 RPM at 100% and tracks with the mfg. data for these fans.

When running with manual power control in CC2 if I take the fans to 0% they don't stop, but slow to about 400 RPM. Is this normal behavior?

Otherwise, using 4 thermal probes and automatic fan power I'm really pleased with the performance. My PC is very quiet, except under heavy load and even then it's still pretty quiet.
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With fan RPM monitoring, you will never be able to turn the fan off completely. If you disable fan monitoring, the fan RPM will go to 0.

It has something to do with PWM control, perhaps the CF experts can better explain that.:)


CF Mark

The fan has to have power to read the RPM.
So when RPM monitoring is turned on, the fan will get a quick pulse of power now and then so the RPM can be read.