Fan speed offset to all other fans

[peppi0304]

Noctua explains that at certain speeds the noise of two fans can create a new irregular sound.
https://noctua.at/en/fan-speed-offset-explained

I do already see the Sync Curve but that utilises that all fans operate under the same condition. But I have different curves for CPU, GPU and I only want them to not match speed by a given offset. Or Beat Frequency as mentioned by Noctua.

I guess the current workaround would be to make a maximum mix out of all curves and then set a sync for each fan.

[Rem0o]

Try this:

Apply a slightly different offset on each controls instead? So if multiple controls are on the same fan curve, the offset will make sure they are all a bit different.

[peppi0304]

I didnt know about this option so thank you for that but the end result is still the same that all of the fans still rely on the same graph / fan curve.

[Rem0o]

Not quite sure I understand what you want to do then. You got fan curves already for different fans. Now you want to avoid having multiple fans at the same exact rpm. You can simply adjust your curves so they never cross in %?

[peppi0304]

You got fan curves already for different fans. Now you want to avoid having multiple fans at the same exact rpm.

Yes this is what I want. But how would I adjust the fan curves that rely on two different temperatures? They will meet at some point unless i dont use the full range of RPM for each fan.

It would also be nice to set the offset in absolute RPM and not relative percentage

[Rem0o]

But how would I adjust the fan curves that rely on two different temperatures?

Either you adjust both, or this is where the "Control" offset I suggested comes in.

If you got more than 1 fan on that mix fan curve, put the offset on the control.

Could you send a screenshot for your whole config? I feel like it would be easier to talk the same language then.

[peppi0304]

I currently only operate with one fan and i have ordered fans just yesterday. But here is a config of how i somewhat imagine it to look like

My pc is in the closet and is a passive build and above 55% I hear it outside so this is the maximum of speed. And below 40% they stall. For example if the CPU has 80°C and the GPU has 73°C they both operate at 40%. And if I would give and offset to one of the fans i just move the problem to a different temperature

beatfrequency.json

[Rem0o]

Well that's quite the narrow range you got.

And if I would give and offset to one of the fans i just move the problem to a different temperature

Well no matter how that offset would work, you will have 1 fan running lower than the other. By the way, a difference of 50-100 rpm will not impact temperature in any meaningful way. So I wouldn't worry about that for the purpose of your noise concern.

I currently only operate with one fan

You say you operate with one fan only at the moment, so you are worried about a theoretical constructive noise interference (beat frequency) between your current and future fans?

I would personally experiment once every fan is plugged in, in its respective place. Find the threshold you start hearing your fans, then see if there is an annoying hum in the first place. There might not be any in practice.

What I would do personally, is do a mix curve with GPU + CPU in there. So all fans monitor the hottest temperature. Assign that to all my case fans, and run a 1-2% offset on each different control so their rpm never align.

Side note: Did you know you can setup for graph in RPM instead of %? Three dot menu on the graph -> RPM mode.

[peppi0304]

So in short: The only solution is mixing as I stated in the begining. Which is annoying when all the fans start spinning just because the CPU gets hot.

It would be cool if this would be a feature in the future. Where you can enter each fans amount of blades and the program looks to not match the frequency and gives a certain offset so the fans dont match each other.