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Fan spins at max RPM despite CPU being idle

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YNK93 6 days ago

Hi! Last week I built my first PC. I was a bit nervous about accidentally breaking parts, but it actually went quite well. The only thing it was missing, was an operating system, so earlier today I installed Windows 10 to my SSD. After about half a minute I realized that one of the fans was making a lot of noise. Not long after Windows had succesfully booted, the GPU's fans automatically turned off because it wasn't being used. That's when I knew the sound was coming from the CPU cooler, the Wraith Stealth. I immediately downloaded NZXT's Cam software to try and figure out what was going on. Apparently the fan was spinning at ~1660 RPM (which is its max speed according to Cam) despite the fact that it wasn't under any load.

What could be the reason for this and how do I fix it?

Also, I don't know if this has anything to do with the fan spinning so fast, but it's making a strange noise. Here's the audio, you have to turn the volume up high to hear it though: https://vocaroo.com/i/s0N03jtk7Men

Here's a screenshot of the Cam software: https://imgur.com/a/ulEkJMQ

I'm not sure if this info is really necessary, but here are the specs:

  • Ryzen 5 2600 (with Wraith Stealth installed)

  • Sapphire RX 580 Nitro+ 8GB

  • Kingston HyperX Fury 8GB 2666MHz RAM

  • Crucial MX500 250GB M.2 SSD

  • ASRock B450 Fatal1ty Gaming-ITX/ac

  • Corsair SF450 PSU

Comments Sorted by:

kschendel 1 Build 2 points 5 days ago

The fan is plugged square into the CPU fan header on the motherboard, and it's not accidentally offset by a pin?

You should have some sort of fan control in the BIOS, see if you can control the fan at all there, or if it spins at full speed no matter what. If it's OK in the BIOS but full out in Windows, I'd look for a driver issue of some sort; I don't do Windows myself so I can't be more specific.

YNK93 submitter 1 point 5 days ago

I checked the motherboard manual before installing the CPU cooler, to be sure that I was doing it the right way. I just turned off the system, took a good look to see if I didn't accidentally install the header the wrong way, but it was installed correctly. I'm going to check and see what I can find it the BIOS, thanks for the suggestion.

Tetsuclaw 5 Builds 2 points 5 days ago

That motherboard does have fan controls in the BIOS. From looking through the user manual online it seems very close to how I have it on my Asrock AB350M Pro4 board where you can use a preset fan curve or set your own. Around page 66 is where you will find it. If the fan is plugged correctly into the CPU fan header on the motherboard then it is likely set to run at 100% in the BIOS.

I did set a very non aggressive fan curve in my BIOS as to limit noise as much as possible. My fan speeds cap out at 55% because I got such an over powered cooler for my CPU.

YNK93 submitter 1 point 2 days ago

Thank you so much for your reply. I really appreciate it that you went looking through the user manual.

I didn't know that fans automatically run at 100%. Is that normal? I thought the motherboard would handle it so that it would set up its own fan curve according to the temperatures. I actually checked out the BIOS a couple days ago and tried out different fan modes, which gave me the following results:

  • Silent: 1580 RPM

  • Standard: 1668

  • Performance: 1850

  • Full speed: 1900+

I thought that 1580 is quite loud for a silent mode haha. Did ASRock set it to be this high because they want to be sure that the processor is properly cooled, or could there really be something wrong with my cooler and/or motherboard?

pcbldragain 1 point 2 days ago

Some bios set a limit on low speed due to PWM and the fan stopping at too low a speed. I don't know if this is your issue, but heard of people complaining about not being able to set it lower.

Tetsuclaw 5 Builds 1 point 2 days ago

Well with my motherboard it did have a rather aggressive fan curve for the default setting but it wasn't full blast all the time. Though I got a very quiet cooler by design but having it so quiet I can't hear if the PC is on or not is a really nice thing to have. I am currently running a Dark Rock Pro 3 and I love it. Stock coolers won't be that silent but it doesn't need to be a jet engine either. The Ryzen coolers are far better than the old FX stock coolers. If you are not overclocking you may get away with setting a lax fan curve for less noise and be fine.

Did ASRock set it to be this high because they want to be sure that the processor is properly cooled, or could there really be something wrong with my cooler and/or motherboard?

Default settings that you do not like does not make the board defective especially when you can set them to something that works better for you. Many people are not that sensitive to PC noise so most people may not even notice and I guess Asrock just wanted better cooling by default settings. People got kids or other sources of noise that will easily drown out any PC noise. I do care about noise from my case so my PC is quiet enough I can hear the fridge while in another room over my PC which is really quiet. It seems you and I have that in common lol.