Even now 3 years forward its still an issue. I've got four noctua's on an external radiator connected to the Asus Ext Fan board - and have some pretty well thought out curves and controls built in to the AI Suite/Fan Expert(??) 4 software ....and they all four randomly see to do whatever the heck that want to at any given time
30% should be ~950rpm - but the fans mostly sit at 1500+
Fan spin up and spin down settings all reset each time I reboot.
All four fans are attached to the CPU temp .... so you'd image that they'd all be roughly the same speed. Not 750 on one, 2500 on the next 1200 on the next and one sitting at zero. And I have not only verified RPM's with a hand held RPM laser, but I've monitored all with 2 separate HW Monitor apps ... and they all agree with each other and physical facts. Yet the fans do as they please.
Two things of note .. I can at any time touch something to make the "Apply" button appear ... and then do this to all four fans .. and they all return to normal control. But hours later go back to running amuck.
2nd, I noticed that things got a little more stable when I rose the minimum RPM further away from the fan's natural shut off point. For these noctua's that was about 400 to 550. I raised the threshold to 30% which should be ~1000rpm - in reality closer to 1100-1200 rpm .. which I'd be happy with, it they all decided to play nice.
It's not a fan or cable issue .. as I can "poke" at the app and get them to respond. They just don't continue to do so.
Its almost as if expert fan 4 software some how falls asleep or forgets how to accurately talk to the external fan controller .. IDK .. but I'm looking for other solutions at this point. If you can't trust your software or hardware ... go elsewhere.
MAXIMUS XII EXTREME | Intel Core i9-10900KF | EVGA RTX3080 Ti ULTRA HYDRO COPPER | CORSAIR DOMINATOR PLATINUM
I have problem with fans rapidly kicking in full speed without any known reason. They just randomly throttle to the max without any reason. It could be when PC is idle, when it's under load - whatever it could be, fans just push to the max, though a moment ago they just worked silently. Temps can be idle (33-43C) or high load (50-55C), doesn't matter, the glitch comes out. Fans can work flawlessly for a week, or they can glitch dozens of times per one day.
I don't know what causes it, or how long this bug lives - fans can kick in for 1-3 seconds and drop down the speed to set numbers again, or they can work at full speed forever until I manuaally stop or change any option via fan xpert.
Problem occurs only when Fan Xpert is used (unproven, but I have strong feeling about that, because no issues when UEFI Qfan utility is used).
As for fans - ATM, I use 6 nb eloops, connected to 2nd and 3rd cha_fan via 4pin splitter, 1 by 3. Before, I used 6 vardars, each connected separately, 4 of them I've connected with 1->2 splitter after a while. All this time I had such a problem. I had this problem before Spectre/Meltdown, with AI Suite temporary fault, and afterwards.
MB is X hero.
Using Qfan only is not a variant, because ASUS is a joke here because of 75C limit and aabsence of GPU bind. I have silent custom loop with CPU thrown at 5 GHz at high voltage, so I can't decrease time-to-time spikes up to 79C. That is said, Qfan is no go variant for me. Xpert has an option to break 75C limit, plus, it has an option to bind fan speed to GPU temps - the most intensively used piece of hardware in my PC.