Z170 Extreme4 How To Set CPU Fan Speed to 0%

Short version - CPU fan Used to stop spinning when cpu was cool, now it will never stop no matter how cool cpu is.  How can I get the cpu fan to stop spinning when not needed?

Long Version - When I first bought the Z170 Extreme4 motherboard, the cpu fan(which came with the Intel I7-6700 at 65watts) would stop spinning when the CPU was cool enough below a certain level. After some bios updates to prevent the system from hard locking or rebooting at random, it stopped turning the cpu fan off.  No new bios updates fixed it.  Later, after I replaced an SSD with a new one, the cpu fan would shut off again. 

Somehow, replacing that SSD fixed whatever the issue was.  Now, after a new windows update two days ago, it no longer shuts off.  Even going back to the old version of windows, it no longer shuts off.  Despite the windows update screwing it up, I think it is a bios issue.  When the SSD trick worked, it had nothing to do with windows because windows was cloned from one SSD to the other.  Even before that it worked and then didn't work with the same version of windows on the same SSD.

I am not sure what version of the bios initially broke the ability to go fully silent.  It was before 2017, though.  When the SSD trick managed to get it stopping correctly again, I was on Bios version 7.00.

Now that it no longer works, I updated to the newest(non-beta) bios, version 7.20 at the time of this writing.  It will still not stop spinning.  I could go all day in the past with it never spinning up even once, even during summer with no overheating issues.

I have it set in Fan-Tastic tuning in bios to 0% for all but two temperature ranges(and have tried various other combinations) of 0% and higher) but it ignores all settings and won't go lower than 10%.  A-Tuning also ignores 0%.

I want my silent PC back.  It generates minimal heat and does not need the cpu fan always going.  Any ideas?

I do not find any of your questions insulting.  They are important to ask.

I knew for a fact that the fan was not spinning because I could look inside and see that it was not spinning.  Whenever something used the CPU sufficiently it would spin up until it was cool enough, then turn off again.  Now, I did not look at all times, but when I did, it was off.

With the cooler plugged into CPU_FAN1, I used the Fan-Tastic Cooling setting to set the plan to 0% fan speed(if it cannot go to that it should not have that option).  It was not from the factory like that, however it accepted that setting when I first received it or after a bios update, since I updated the bios when I got it.

Currently the fan is spinning at 1020RPM according to A-Tuning and also SpeedFan.

For much of the past two years, when 0% was accepted as a minimum, the only fan I have had was a CPU fan.  It worked very well for everything I have used it for.  I added a video card very late last year, and it continued to work perfectly with 0% fan speed.

The SSD situation was very odd.  When I plugged the drive in, the bios did not want to boot from it and gave an error that it could not.  However it would then boot it anyway about 6 seconds later(or whatever the default delay is to boot from EUFI.)

When that error hit for the first time, and after every reset after that(which also gave that error) it ran at 0% fan speed just as I had it set in the FanTastic settings.  It is possible that when I cloned the first SSD onto this new one that something in the boot sector, or whatever modern drives use instead for UEFI, confused the bios.  Windows must have corrected it somehow when it did the feature update.

At the time, it was a cloned operating system in the same computer.  There were no hardware or settings changes except perhaps boot order in the bios.

As to the stock cooler itself.  I have never seen the cooler go below 900rpm and even getting into the 900 range is very rare.  It is usually at 1000 or higher no matter what.  A quick test with speedfan, since it was open, showed no change in fan speed until I increased it to 25%, when it increased to about 1260RPM.

parsec wrote: tannim wrote: First, let me say if some of my comments and questions are insulting to you, I apologize, that is not my intent. But some of the things you wrote simply do not seem to make sense, or seem impossible. I imagine that is caused by missing information. I'll also be lecturing about a thing or two, but you have every right in the world to do things your way. So when using the Intel stock CPU cooler, connected to the CPU_FAN1 header, with the UEFI/BIOS version from the factory when you first began using this board, the CPU cooler's fan would stop completely, 0 RPM, below a certain (unknown) temperature? Did you configure the CPU_FAN1 header to behave that way, at that time? Or did it work that way, 0 RPM at times, with the default CPU_FAN1 fan speed profile in the UEFI? I must ask how you knew the CPU cooler's fan was at 0 RPM? By seeing a 0 RPM reading in a monitoring program? Or by visually seeing the fan not spinning? Or both? The fan on the Intel stock CPU cooler was never meant to not spin at all. At ~20% PWM signal or less, it would still be spinning but below the threshold of audibility. Which is why I asked if you really know the fan was at 0 RPM. I'm surprised that was ever allowed, and not surprised that was changed if it was allowed. Also please understand that for years with any manufacture's mother board and UEFI/BIOS, that a 0 RPM CPU cooler fan speed is considered a bad hardware error situation, and is tried to be avoided. Some board's I've seen display error messages if the CPU cooler's fan is below 500 RPM. Which is why you cannot set the fan speed to lower than 10%. ASRock, etc, does not want to be responsible for over heating processor complaints and damage reports from customers. Actually, we are aware that Intel released defective CPU coolers with some of their Skylake processors, but normally they did not respond to any fan speed configuration below 50% PWM, and ran well over 1,000 RPM at any PWM percentage below 50%. I'm wondering if your CPU cooler's fan is defective. ASRock added an option to the H/W Monitoring screen to compensate for the defective Intel CPU cooler fans. That may explain why your fan never stops spinning after a certain UEFI/BIOS update. I assume since you said you have silent PC, that you have few or no fans mounted in the PC case, or ultra quiet, slow fans barely spinning? Replacing one SSD with another, in and of itself, could not possibly "fix" the "bug" of the CPU cooler's fan not being able to be at 0 RPM. There must have been a change in the fan speed control software between the two Windows installations on the SSDs. For example, you had A-Tuning set to Auto-Run on the old SSD, but not on the new one, or vice versa. Running A-Tuning will override the UEFI fan speed configuration, but only when A-Tuning is running. Or it is related to a setting in your Windows Power Plan. Enough of that, I'll try to give you what you want. First, what is the minimum speed you are currently able to get the CPU cooler's fan down to? If it is not below 1000 RPM, that would indicate one of the defective stock CPU coolers. If your CPU cooler is working normally, move the fan connector to a Chassis fan header, and try setting the temperature being monitored to the mother board. That rarely changes much, and will never go as high as the CPU temperature. Set the temperature as low as possible. In your Windows Power Plan, Advanced settings, under Processor power management, set System cooling policy to Passive. Another possible fix is to connect a fan speed reduction adapter to the CPU cooler fan. UEFI updates are not kept current in a board's manual, so I have no idea what new options you may have, or their configuration.