3 pin fans speed not accurate and RPM Loop

[Wawar9]

Hello,

When I use fan control to control my 3 pins fans (Noctua NF-S12), the calibration, or I could say, the relation between the % and the RPM, seems off.

Version : Fan Control v255
Symptoms :

• If i set a low % load (for example, 20%), fans are actually spinning at a certain RPM (I can see the fan spinning), but Fan Control software does not read any RPM
• Once passed a treshold, the Fan Control RPM indicator catch up and shows a valid RPM number

Extra issue :
If I use the last update (v262), my 3 pins fans don't spin until i ask 50% RPM with Fan Control. If a lower % value is set, the fans start to loop, start and stop, every 10 seconds. Re-calibrate the fans does not work.

Any idea?

[Rem0o]

RPM signaling near the stop threshold is not accurate. As for the V262 behavior, my guess is your start and stop% are badly configured. You may set 0 for those 2 fields, otherwise redo an assisted setup to auto-find those 2 values.

[Wawar9]

Ok, so that fix the start/stop issue, thanks.

However, with v262, when I set my fan to a % that don't show any RPM, the fan goes crazy and do an "RPM LOOP", looping from the minimum value that I've set, to the first % value that indicates an RPM.

[Rem0o]

That's because you try to run the fan precisely at its threshold. You should not operate it in that region.

[Wawar9]

But I don't have the issue with v255.

With v262, the fan don't start below 50%.

v255 : start% = 20% / stop% = 17% / Idle RPM : 20% / Works well, no issue
v262 : start% = 50% / stop% = 47% / ISSUE : RPM loop

If I revert to v255, I can run my fans to 20%, without any issue or RPM loop.

[Rem0o]

Hummm maybe something changed in LHM regarding your motherboard compatibility, because there is no reason from FanControl internal logic's perspective for this to have changed.

[Wawar9]

The MB is an Asus tuf z890. Is there something I can do to fix the issue? Should I wait for an LHM update?