Why is my PC making a humming noise?

There are a few potential reasons why your PC may be making a humming noise. The most common causes are related to cooling fans, hard drives, power supplies, and coil whine from components like the graphics card. Troubleshooting the exact source of the humming can help you determine if it’s a normal noise or a sign of a potential problem.

Possible Causes of Humming Noise in a PC

Cooling Fans

The cooling fans inside your PC are one of the most likely culprits for humming or buzzing noises. Fans generate noise simply due to the nature of their spinning parts and motors. There are a few reasons a fan might start making more noticeable noises:

  • Fan bearings are starting to wear out. Fan bearings operate smoothly when new, but can slowly degrade over time and start to cause friction and humming noises.
  • Fan blades are vibrating against a cable or loose component. If something is obstructing the fan blades or throwing off their balance, it can cause buzzing noises.
  • The fan is accumulating dust/debris. Buildup on the fan blades can throw off the balance and cause vibration.
  • Increased workload and heat are causing fans to run faster. Higher RPMs generally equate to more noise.

Some amount of fan noise is perfectly normal. You’ll want to listen closely to try to isolate if the noise sounds like it’s coming directly from the movement of fan blades, or if it may be coming from elsewhere.

Hard Drives

Hard disk drives (HDDs) contain spinning platters and a mechanical arm that moves to read/write data. Some operational noise comes from the spindle motor that spins the platters, the head actuator arm moving back and forth, and gyroscopic forces from the quickly rotating disks.

Like fans, some HDD noise is completely normal. But certain sounds like grinding, buzzing, clicking, or loud humming could indicate a problem:

  • Failing spindle motor causing extra friction
  • Read/write head malfunctioning and vibrating
  • Platter damage or misalignment causing imbalance
  • Excessive activity and drive operation leading to more vibration

Deteriorating hardware like the spindle motor is one of the most common reasons an HDD might get progressively louder with age.

Power Supply

The power supply unit (PSU) converts AC power from your wall to stabilized, regulated DC power for the PC components. Better-quality PSUs generate very little noise, but cheaper models can produce some coil whine or humming.

Sources of power supply noise include:

  • Electromagnetic coil whine from transformer, chokes, or filter capacitors
  • Fan noise if there is a built-in cooling fan
  • Vibrations from loose or improperly mounted components
  • Electrical ripple or oscillations

Excessive noise from a PSU usually means poor component quality or damage. But a healthy PSU might also get louder under very high loads when components work harder to deliver extra power to the system.

Coil Whine from Components

Coil whine refers to high-pitched ringing or buzzing caused by vibrations in the coils or chokes on PC components like the graphics card, motherboard voltage regulators, CPU power chokes, etc. It occurs when alternating current flows through an inductor coil, causing it to vibrate from electromagnetic forces.

The noise varies based on how much current is flowing through the component. More demanding tasks increase power draw, resulting in louder coil whine. It’s most commonly heard from GPUs since graphics rendering causes high power fluctuations.

Coil whine is generally harmless, but can be annoying in a quiet room. Unfortunately coil whine simply results from the laws of physics and electrical design – there’s no way to fully eliminate it in susceptible components.

Locating the Source of the Noise

Figuring out which specific component is generating humming or buzzing noises in your PC can take some troubleshooting. Here are some tips:

  • Open the case and listen closely to isolate the general location of the noise while the computer is running.
  • Carefully stop each case fan with your finger to see if the noise changes or stops. This can help rule out a bad fan bearing.
  • Check if the noise seems to be coming from the hard drive area.
  • See if the noise gets louder during heavy graphics tasks, which points toward coil whine from the GPU.
  • Try disconnecting unnecessary peripherals and external drives to remove them as noise sources.
  • Use a tool like SpeedFan to change fan speeds – noise will increase/decrease along with RPMs if a fan is the culprit.
  • Replace the PSU if you suspect it may be causing buzzing or humming noises under load.

With focus and patience, you can systematically isolate the source of most mystery PC noises. If needed, replacement fans, hard drives, power supplies, or even motherboards and GPUs are available.

Is the Noise a Problem?

Once you’ve identified the culprit for the humming or buzzing sound in your computer, you need to determine whether it’s simply a normal operational noise or a symptom of a larger problem.

  • Some fan, drive, and coil whine noises are completely normal, especially during demanding tasks. Don’t worry about noises from components working as expected.
  • Buzzing/grinding from fans or hard drives often means a component is starting fail. Replace them before total failure.
  • Loud hum that occurs randomly or only under light loads may indicate an issue like a bad PSU capacitor.
  • Loose casing and hardware can amplify noises. Ensure all components are properly installed and secured.
  • If the noise wasn’t there previously, pay attention – a new noise likely signals a developing problem.
  • Noise that corresponds with crashes or performance issues is always a concern and could mean component failure.

Monitor for changes in noise pitch, volume, and occurrence to detect hardware degradation over time. If the humming only started recently and is consistently loud, have the PC serviced to address the issue before it worsens.

How to Reduce Noise from a Humming PC

Here are some tips to quiet down a noisy computer when the humming or buzzing is disruptive:

Clean Out Dust Buildup

Use compressed air to thoroughly clean dust from fans, heat sinks, and PC case vents. Dust traps heat and forces components to work harder with loud cooling fans.

Check Fan Curves in BIOS

The BIOS controls fan speed curves – tweak them to reduce overall fan speeds and noise levels. Just watch temperatures to avoid overheating.

Replace Old/Failing Cooling Fans

Install higher quality fans with fluid dynamic bearings, dampeners, and quality motors engineered for quiet operation and longevity.

Add Fan Silencers

Adhesive silicone fan silencers can dampen fan noise and vibration. Or install fans in rubber grommets.

Use Sound Dampening Materials

Special foams and noise absorbing materials applied inside the case can mute humming.

Improve Airflow

More airflow means components stay cooler with lower fan speeds. Add more intake/exhaust fans or improved CPU and GPU coolers.

Isolate on Rubber Feet

Soft rubber computer case feet prevent transmission of vibration noise from hard surfaces.

Limit Power Draw

Less demanding loads mean less heat and noise – cap FPS, reduce overclocks, or enable power-saving modes.

Get a Quieter PSU

Higher efficiency and quality PSU units often have much lower noise output.

Use Noise Cancelling Headphones

Good active noise cancelling headphones block out PC noise entirely so you can focus.

Relocate PC Position

Place the computer tower further away or in an enclosure to distance yourself from the noise source.

With some troubleshooting and a few upgrades, you can usually control excessive humming and buzzing noises in a desktop computer. But some hardware-based noise is inevitable during heavy workloads.


Humming or buzzing noises coming from your PC are typically caused by cooling fans, hard drives, the power supply, or coil whine from components like the graphics card. Determine the exact source of the noise by listening closely while the computer is running and using a process of elimination. Some amount of noise is normal, especially during demanding tasks. But loud or worsening humming often means a fan or hardware component is failing and needs replacement before total failure occurs. Reduce annoying PC humming using cleaning, upgrades, sound dampening materials, relocating the tower, capping power levels, and other noise mitigation techniques. Be proactive at diagnosing the cause of new humming noises and fixing deteriorating components to prevent performance issues.

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