computer fan constantly changing speed

cpu stock fan fluctuating and constantly changing speeds on new PC

reddit.com › r › buildapc › comments › eg57li › cpu_stock_fan_fluctuating_and_constantly_changing

I've just answered this somewhere else. Try the settings below. 25C/40 60C/50 65C/80 70C/100 What this does is that, at lower temps, the fans will not ramp up as fast or as intensely, and it will only ramp up upon actual use. There's probably also a ramp up and ramp down speed adjustment. Set it to the highest you can find. Should be 0.7s and 1.0s respectively. Answer from KohGeek on reddit.com

PCPartPicker

pcpartpicker.com › forums › topic › 267234-constantly-changing-fan-speed-help

Constantly changing fan speed? Help!!! - PCPartPicker

I think the problem is a combination of the monitoring being extremely sensitive to changes in temps and applying too much or too little voltages / PWM signal to the fan for those moments. Sadly no way to smoothen out or delay fan spin up and down time. This is problematic with CPU's which ...

Tom's Hardware Forum

forums.tomshardware.com › home › components

CPU fan speeds up for no reason, then slows down again | Tom's Hardware Forum

November 23, 2017 - When the fan speeds up that generally means the CPU is generating more heat, i.e. more processing. The thermistor could be bad but that would be very rare in my experience. I would look at what processes are running when the CPU starts spinning up. As always check for a BIOS update and besure ...

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cybersided.com › home › random pc fan revving: what causes it & how to fix it

Random PC Fan Revving: What Causes It & How to Fix It

September 17, 2021 - The problem comes when less computationally demanding software creates a larger-than-necessary CPU load. When you notice increased fan speed, take notice of what programs are running.

Quora

quora.com › Why-is-my-computer-fan-constantly-revving-Even-when-its-not-hot-overheating-and-Im-not-on-my-computer-it-revs-it-does-so-constantly-when-I-am-on-it

Why is my computer fan constantly revving? Even when it's not hot/overheating and I'm not on my computer it revs, it does so constantly when I am on it? - Quora

Even when it's not hot/overheating and I'm not on my computer it revs, it does so constantly when I am on it? ... Constant fan revving despite low apparent load usually means something is driving the fan controller to demand more airflow or the control loop can’t reach a stable lower speed.

reddit.com › r/buildapc › cpu stock fan fluctuating and constantly changing speeds on new pc

r/buildapc on Reddit: cpu stock fan fluctuating and constantly changing speeds on new PC

December 27, 2019 -

I have the amd stock cooler on my ryzen 5 3600. I can hear a fan running quickly a bit then slowing down for a couple of seconds, its not really that loud but definitely noticeable and a bit annoying. Checked using HWMonitor and the cpu temp (40-50C) + stock cooler speeds are always fluctuating while everything else is more stable. Is this normal? and is there a way to make it more constant? this happens while pc is idle not even while gaming. Also should I download the latest bios for my mobo? (b450 Tomahawk max). Currently using the balanced power plan instead of the ryzen balanced one which did not make a difference

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Yeah, it’s normal for the fan to speed up

reddit.com › r/buildapc › cpu fan keeps chaning speed for no reason

r/buildapc on Reddit: CPU fan keeps chaning speed for no reason

February 11, 2022 -

Hello, I recently build this PC like a week ago. The CPU fan I believe is the cause here, because I can hear it constantly fluctuating in speed. It will do this all day, everyday, no matter if I have only the internet open up. It's not like i'm opening up a demanding video game and it changes speed, no it will change speed back and forth all day long it's kind of weird, even if i'm just watching a youtube video is keeps speeding up and slowing down and I can hear it because it's loud. Any known fix? CPU fan is a hyper 212 air cooler

Top answer

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its not weird, its completely normal, if configured correctly the fan speeds will vary according to processor/motherboard temperature

2 of 3

Maybe try tuning the fan curve? Fans are usually set to run faster if the temp goes up. That could even be from small load changes on the CPU from background tasks. Probably either your fans need tooned or your cooling is inadequate for that CPU, probably the former.

reddit.com › r/buildapc › pc fans speeding up and slowing back down?

r/buildapc on Reddit: PC Fans Speeding up and Slowing back down?

July 26, 2018 -

Hey guys, I built my PC last November and it's ran well since then but within the past few days I've noticed something that I think is a bit odd.

I bought The Witcher 3 to play when my friends aren't on or when I just want to play a good single player game. While playing, I noticed that my PC fans were speeding up and slowing down what I considered to be pretty randomly. I figured it was since I had a lot of the graphics turned up pretty high so I turned some of them down but the fans still seemed to be fluctuating in rpm's. I then noticed they were doing similar fluctuations while I was playing CS:GO, where I have all but one or two settings turned down as low as possible.

I have an NZXT kraken AIO so I checked the connections plugging in the pump to make sure they weren't loose or anything. I guess that really only leaves my GPU fans and case fans but I'm not sure what I need to do next if there is anything wrong in the first place.

My build is as follows:

Case: NZT S340 elite

CPU: Ryzen 5 1600

GPU: Asus Dual Series 1070

CPU Cooler: NZXT Kraken X62

Case Fans: stock NZXT for exhaust and stock kraken fans for intake

Edit: I usually play with headphones on so this may have started earlier but when i was playing The Witcher using my speakers is when I first noticed the fans doing this. I also had my headphones off when I was playing CS:GO and noticed it.

Top answer

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Try turning on the CPU fan smoothing option in your BIOs. I've had a similar problem with a Ryzen 1700 & 2700X. Ryzen boosts, has a voltage spike, results in a temperature spike and the fans ramp up to compensate. In my case it was most noticeable at idle where light tasks (like a web browser) would make the fans ramp up for a second, which is more annoying than a consistent drone. By adjusting the CPU fan smoothing you can made the fans less 'bursty' when responding to CPU temperature spikes. You could also make your fan curve less aggressive. Alternatively you could try overclocking which disables the boost and locks at a clock speed. This thread has a bit of discussion about it.

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Fans spinning faster when components are under load is normal. Sounds like you just need to set a custom fan curve so they don't ramp up in such a quick fashion. Should be able to get a CPU & case fan curve in your BIOS. GPU fan curve with your Nvidia driver, MSI Afterburner or possible an ASUS graphics card utility?

reddit.com › r/buildapc › my computer has recently started increasing and decreasing fan speed repeatedly, almost like a siren. why?

r/buildapc on Reddit: My computer has recently started increasing and decreasing fan speed repeatedly, almost like a siren. Why?

May 22, 2021 -

Even when idle and not in a game or program that requires performance from CPU or GPU, the fans get pretty loud sometimes. And sometimes it has that thing which it is doing right now: Fans get LOOOOOOOOUD silent..... LOOOOOOOOUD silent....... LOOOOOOOOOOUD silent..... and it keeps going and is somehow really annoying. Why is that so? How can I fix it?

Edit: The intervall is like 5-7 seconds, so in that time it gets loud, stays for a second or two, then gets silent, and repeats on and on just like that.

Top answer

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Youre bouncing between a node on the fan curve. Ie. your fan curve says that below 70c fan speed is 25%, and above 70c fan speed is 50%. Your PC is going to 71c, then 69c, then 71c etc. You should be able to change the fan profile in BIOS.

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First I would ask what kind of motherboard you have because depending on the model your BIOS might allow you to have custom fan profiles. It is very possible that your temps are at the cusp of where they switch between being high rpm and low rpm. Also it depends on your fans, if you have PWM fans they should transition instead of switch between modes, usually fans like the Noctua Redux only have three fan modes, low / med / high so that might be something to look at as well. However I would recommend looking for fan settings first. Most motherboards that have this option allow some basic manipulation through the BIOS, but with more detailed tweaking using applications for example ASUS motherboards have AI Suite.

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The Windows Club

thewindowsclub.com › the windows club › general › cpu fan runs at full speed all the time

What to do when your CPU Fan runs at full speed always?

Do this if your computer fan is running at high speed all time. The CPU needs a fan to cool down the processor. It runs faster when the temperature of the CPU increases.

Published October 5, 2024

TULARC

stason.org › TULARC › pc › 3b1-faq › 6-3-Why-does-my-fan-sometimes-speed-up-and-slow-down-Shoul.html

6.3. Why does my fan sometimes speed up and slow down? Should I replace it?

Gil Kloepfer theorizes the reason for this happening is that the 12VDC fan is constantly running with too little current due to a resistor wired in series with the power supply when the thermal switch is in its normally open position.

Tom's Hardware Forum

forums.tomshardware.com › home › systems

Computer fans keep speeding up and slowing down? | Tom's Hardware Forum

November 5, 2018 - I had this kind of issue with a MSI x370 Krait Gaming MB. I tried changing the fan curves settings but it looked like the MB and CPU CoolerMaster cooler were not matching signals, thus it kept revving up and down while idle. I "solved" by setting a constant speed under BIOS menu.

Tom's Hardware Forum

forums.tomshardware.com › home › cooling

[SOLVED] - Cpu fan speed revving up and down constantly | Tom's Hardware Forum

Top answer

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I got it working a bit better, albeit still a bit loud. I guess I'll just deal with it for now and upgrade later to a Noctua or something. Thanks for the help/advice though. Self awarded Best Answer removed by moderator

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Look for EZ Mode - Hardware Monitor in Bios see page 42 https://download.msi.com/archive/mnu_exe/mb/E7C02v1.3.pdf

HP Support Community

h30434.www3.hp.com › t5 › Gaming-Notebooks › Erratic-Fan-Speed › td-p › 8322775

Solved: Erratic Fan Speed - HP Support Community - 8322775

March 19, 2022 - To begin with, go to "power options" -> "change advanced power settings" -> "processor power management" -> "maximum processor state" and lower it to avoid overheating or fan noise.

Tom's Hardware Forum

forums.tomshardware.com › home › components

One of my pc's fan's(or cpu or gpu fan) keeps increasing and decreasing speeds | Tom's Hardware Forum

July 16, 2017 - What they do is monitor the TEMPERATURE of either the CPU chip inside (for the CPU_FAN header) or the mobo (for the case fans) and alter the speed of the relevant fan system to cool just enough to keep those temperatures at their correct values. When you do lost of work and generate more heat, the fans speed up. When you take a break and temperatures fall, the fans slow down. ... You should realize that any fan is supposed to change its speeds as you change the workload.

Groovy Post

groovypost.com › how-to › stop what’s revving your cpu fan constantly in windows 10

Stop What’s Revving Your CPU Fan Constantly in Windows 10

July 14, 2021 - The cpu fan was constantly running and things were staying hot. Closing most of my open Chrome tabs helped, but I also tried another tip: using Change Advanced Power Settings> Processor Power Management, I reduced the Maximum Processor State from 100 percent to 90 percent.

Tech Support Forum

techsupportforum.com › home › forums › hardware support › motherboards, bios|uefi & cpu

[SOLVED] CPU Fan constantly changing speeds | Tech Support Forum

September 26, 2012 - Re: CPU Fan constantly changing speeds I would try re-seating the CPU. Sometimes the stock CPU compound doesn't get pushed out all the way and doesn't cause any problems for quite a while.

reddit.com › r/buildapc › pc fans randomly speed up, even when idle

r/buildapc on Reddit: PC fans randomly speed up, even when idle

March 2, 2022 -

For the past couple of months I had this issue with my 3 year old PC where the fans randomly speed up, mostly during boot and then randomly while its idle or while Im playing. Now, Im not really sure if its just the case fans, CPU fan or both. But is it something to be concerned about?

Specs:

GPU: Asus GeForce RTX 2060 Dual Evo

CPU: Intel Core i5-9600k

MOBO: ASUS ROG Strix B360-F Gaming, S-1151

RAM: Corsair Vengeance LPX DDR4 2400mhz 2x8GB

SSD: Kingston A1000 480GB M.2

PSU: Corsair Vengeance 750M, 750W

CPU Cooler: Cooler Master Hyper H411R

CASE and case fans: Phanteks Eclipse P400 Glass, stock fans

OS: Windows 10 Home

Top answer

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It's likely the setting within bios (PWM) basically giving the fans the freedom to ramp up and down depending on what your system is doing or what the temps in the case are like for the cpu. It's not an issue as such, I disable pwm and run my fans fast to reduce temps constantly.

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download speedfan and watch jayztwocents video from yt on how to set it up. It should fix your problem.

Quora

quora.com › Why-does-my-fan-keep-fluctuating-in-speed-by-itself

Why does my fan keep fluctuating in speed by itself? - Quora

Seriously though, there are a lot of things that can cause a fan to fluctuate in speed, such as dust accumulation, a dirty blade, or even something blocking the airflow. If you've ruled all of thos...

The Windows Club

thewindowsclub.com › the windows club › general › how to control fan speed on windows computers

How to control Fan Speed on Windows computers

Here, look for RPM settings. Once found, select the CPU fan to increase or decrease its speed with RPM as a unit · Save these changes and press Esc till you reach the menu option. Read: Best practices to keep your computer cool.

Published November 17, 2025

Dell

dell.com › dell community › desktops › inspiron desktops

My fans are running at max speed constantly | DELL Technologies

March 3, 2023 - Corrupted video drivers can cause high fan speeds. Open Device Manager and click View>Show hidden. Then look for any entry that's marked as having a problem and see what error message is listed. Also look for any "Unknown" entry in DM. Right-click each "Unknown" and Uninstall. Then, without rebooting, click Action>Scan for hardware changes on the DM toolbar.