Silent Running: How to Fix a Noisy Computer Fan

The computer fans in your desktop PC or laptop is there to keep things running smoothly. However, if you can barely hear yourself think over the cacophony of fan noise emanating from your computer, it’s probably time to diagnose the problem.

An internal fan will work harder as hardware temperatures rise, but there’s probably something more going on if your PC constantly sounds like a wind tunnel. It could be a major issue, a minor inconvenience, or something in between. Here are a few things to try.

Check What Software Is Running

Before you rush to grab your screwdriver, look into what software is currently running, the resources it’s using, and whether that fan noise is warranted. It may help to download a program that can monitor your CPU temperature. We recommend using Core Temp(Opens in a new window) for Windows and Fanny(Opens in a new window) for Mac. Both programs are free and easy to use.

On a Windows machine, press Ctrl + Shift + Esc to bring up the Task Manager and click the More Details button. If you’re on a Mac, press Ctrl + Space and search for Activity Monitor. If you aren’t doing anything intensive at the moment, your CPU usage should be low—less than 20% or so.

If your computer is sitting idle and your CPU is busting out 100% of its power, look through that list to see what program is eating up those cycles. Maybe you have something running in the background you forgot about, or you could be infected with malware that is using your PC’s resources without your knowledge.

If the fan noise only kicks in when you’re purposely doing something intensive, like gaming or converting a large video file, then that’s the desired behavior. However, that doesn’t mean you have to deal with the loud whirring and whooshing noises. It’s time to look closer at the hardware itself.

Give Your PC Room to Breathe

(Photo: Joseph Maldonado)

While your computer doesn’t actually breathe like a human, it does need enough room for air to circulate around your PC. Anything that hinders airflow is going to overheat your PC, pushing your fans to spin harder and harder to achieve desirable temperatures.

You should consider if you have any bad habits that could be making things worse. For instance, if you’re using a laptop, don’t set it on top of a plush surface. This can block the vents that allow air to flow in and out of the computer. Lap desks are a much better alternative.

If you’re using a desktop, don’t cover it with a blanket (you may gawk, but I once saw someone do this because “the lights were too bright”).

Set Up Fan Control

Some PCs run their fans at full blast all the time—this is especially common if you built your own PC and haven’t done any fine-tuning of the cooling hardware.

If your fans are plugged into the computer’s motherboard, you might be able to control them using your motherboard BIOS. You can enter the BIOS menu by pressing a key as your computer boots, usually DEL, F2, or something similar. Then, look for the hardware monitoring section (or something similar).

Every BIOS is a little different, so we can’t walk you through the exact steps. Play around with the fan control settings available to you and see what works.

Some will only offer basic “high” and “low” fan settings, while others may provide advanced fan curves that let you set the fan speed at different CPU temperatures. Some motherboards can control all the connected fans, while others may only be able to control fans that use 4-pin PWM adapters(Opens in a new window) (rather than cheaper 3-pin fan models(Opens in a new window)).

If your BIOS doesn’t have any fan control options, a program like SpeedFan(Opens in a new window) will work too but only if your motherboard is functionally capable of controlling those fans. For graphics cards, MSI Afterburner(Opens in a new window) can help you adjust the fan’s behavior when you’re in a heavy gaming session.

If you can’t control the fans through software—say, if the fans are plugged directly into the power supply rather than into the motherboard—certain hardware accessories can help. Noctua makes low-noise adapters(Opens in a new window) that essentially act as a resistor, reducing the voltage sent to the fan and thus reducing its speed. Fan control knobs(Opens in a new window) offer even more fine-grained management.

Once you get the right speed dialed in, your gaming sessions will hopefully be a bit more peaceful.

Clean Out the Dust

HP Z2 Tower G4 dust filter

Dust is one of those unfortunate inevitabilities when it comes to PCs. Just like blue screens and dead hard drives, you’re going to encounter it at some point. Excess dust means excess heat, which means fans spinning faster to keep things cool—and if you smoke or have pets in the house, the problem can get quite severe.

So grab a screwdriver, open up your desktop or laptop, and give it a good once-over with an air duster (or an electric duster(Opens in a new window), if things are really bad). If your fan is making a clicking sound, or other abnormal noises, this is also a good time to make sure the blades aren’t hitting debris of some kind or a stray power cable.

If you have a desktop PC, consider putting some filters(Opens in a new window) on your intake fans to prevent dust buildup in the future.

Replace a Loud (or Failing) Fan Entirely

(Photo: Zlata Ivleva)

If none of the above fixes seem to help, it may be time to replace your fan. Sometimes, even if a fan is in good working order, it’s just too loud.

Smaller fans tend to be noisier, so if you have a 90mm fan you can replace with something larger (or get rid of altogether without affecting temperatures), start there. Not only will the larger fan be quieter, but the increased surface area of the fins will dissipate heat more effectively.

For the custom builders out there, CPU coolers, which come in air and water cooler varieties, are a popular way to keep the processor especially cool. If your CPU heatsink is on the dinky side, swap it with a larger one.

Other times, a fan may be on its way to a dusty grave. This can often result in a clicking, buzzing, or grinding noise that’s hard to ignore. You might be able to fix this with a drop of sewing machine oil(Opens in a new window) in the bearing, but this is best done before you experience symptoms. If this doesn’t help, it’s time to swap in a new fan.

As you search for a new fan, be sure to pay attention to the “CFM” and “dBA” numbers in the specs—the former denotes airflow, while the latter denotes noise level. With the right fan and a bit of preventative maintenance next time, you can keep your PC from sounding like a jet engine a few years down the line.