Where to find CPU fan speed controls

CPU fan speed lives in your computer's BIOS or UEFI — the firmware that runs before Windows or macOS starts up. You reach it by restarting your computer and pressing a specific key during startup, usually Delete, F2, F10, or F12 depending on your motherboard manufacturer. Your motherboard manual or the manufacturer's website lists which key to press for your exact model.

Once you are in BIOS, look for a section called "Monitor", "Power", "Hardware Monitor", or "Fan Control". The exact name varies by manufacturer — ASUS, MSI, Gigabyte, and ASRock all use different layouts. If you cannot find it on the first screen, use the arrow keys to navigate through the menu tabs at the top.

Some computers also let you change fan speed through Windows or macOS software instead of BIOS. Laptop manufacturers like Dell, Lenovo, and HP sometimes include fan control in their system software. Desktop motherboard makers like ASUS and MSI sell separate control programs for their boards. Check your manufacturer's support page to see if software is available for your specific model.

Key Takeaways

  • CPU fan speed is controlled in BIOS or UEFI, which you enter by restarting and pressing Delete, F2, F10, or F12 during startup.
  • Most BIOS menus have a "Monitor" or "Hardware Monitor" section where you can set the fan to manual mode and choose a percentage or RPM.
  • Automatic mode (also called "Smart Fan") adjusts speed based on temperature and is the safest choice for most users.
  • Raising fan speed cools the CPU better but makes your computer louder and uses slightly more power.
  • Some laptops and branded desktops offer fan control through Windows or macOS software instead of BIOS.

Automatic versus manual fan modes

Most motherboards offer two main modes: automatic (often called "Smart Fan" or "Auto") and manual. Automatic mode reads your CPU temperature and adjusts the fan speed up or down on its own. This is the default setting and works well for most people because it keeps your CPU cool without making unnecessary noise when the computer is idle.

Manual mode lets you set a fixed percentage or RPM (revolutions per minute). If you choose manual, you control exactly how fast the fan spins — 30%, 50%, 100%, or whatever the BIOS allows. The downside is that if your CPU gets hot and you have set the fan too low, the temperature can climb without the fan responding. Manual mode is useful only if you know what you are doing and plan to monitor temperatures yourself.

A third option, available on some boards, is a custom curve. This lets you create a rule like "30% speed at 40°C, 50% at 50°C, 100% at 70°C". Custom curves give you control without the risk of manual mode, but they take more time to set up correctly.

How to set fan speed in BIOS step by step

Start by restarting your computer. As it boots, hold down the key for your BIOS (Delete, F2, F10, or F12 — check your motherboard manual if you are unsure). You should see a blue or dark screen with white text appear before Windows loads.

Once inside BIOS, use the arrow keys to navigate to the "Monitor", "Power", or "Hardware Monitor" tab. Look for an option that says "CPU Fan Speed", "Fan Control", or "Smart Fan". Highlight it and press Enter to open the settings.

If the option shows "Auto" or "Smart Fan", your fan is already in automatic mode and you can leave it there. If you want to change it, select "Manual" or "Fixed" and press Enter. You will then see a field where you can type a percentage (like 50) or select from a list. Enter your desired speed and press Enter to confirm.

After you change the setting, look for a button or menu option to save and exit — usually F10 or a highlighted "Save" option at the bottom of the screen. Press that key, confirm the save when prompted, and your computer will restart with the new fan speed.

What fan speed should you actually use

For most people, leaving the fan on automatic is the right choice. Your motherboard manufacturer has already tuned the automatic curve to keep your CPU safe while staying reasonably quiet. Changing it usually makes things worse, not better.

If your computer is very loud, you might lower the fan speed slightly — try 40% or 50% in manual mode and monitor your CPU temperature for a few minutes using a program like HWiNFO or Core Temp. If the temperature stays below 80°C under normal use, you are fine. If it climbs above 85°C, raise the speed back up.

If your computer is overheating (temperatures above 90°C during normal work), raise the fan speed to 70% or 80% and see if that helps. If temperatures are still high, the problem is usually dust buildup in the heatsink or poor airflow in your case, not the fan speed setting. Cleaning the heatsink fins with compressed air often solves the problem faster than adjusting BIOS.

Changing fan speed in Windows or macOS software

If your computer came with fan control software, you can usually find it by searching your system for the manufacturer name plus "fan" or "control center". Dell machines might have Dell Power Manager, Lenovo laptops might have Lenovo Vantage, and ASUS boards might have AI Suite or Fan Xpert.

Open the software and look for a "Fan" or "Cooling" section. The interface varies widely, but most show your current CPU temperature and let you switch between automatic and manual modes. Some display a graph showing the relationship between temperature and fan speed. Make your changes, explore them, and the software will send the new settings to your motherboard.

Software control is easier than BIOS for most people because you do not have to restart your computer. However, the settings may reset if you restart Windows or macOS, or if the software updates. Check your software's settings to see if there is an option to save your preferences permanently.

Risks of changing fan speed and when to stop

Setting the fan too low is the main risk. If your CPU temperature climbs above 100°C, you risk damaging the processor or triggering thermal throttling, where Windows automatically slows down your CPU to cool it down. This makes your computer slower, not faster. If you see temperatures above 95°C, raise the fan speed when ready.

Setting the fan too high wastes power and creates noise, but it will not damage anything. A fan running at 100% all the time is annoying but harmless. If you find yourself constantly adjusting the fan speed to keep temperatures down, the real problem is usually dust, poor case airflow, or a failing heatsink — not the fan speed setting.

If you change the fan speed and your computer becomes unstable (crashes, freezes, or restarts randomly), go back into BIOS and return the setting to automatic. Instability is rarely caused by fan speed alone, but reverting to automatic eliminates that variable while you investigate other causes.

Frequently Asked Questions

What happens if I set the fan speed to 0%?

The fan will stop spinning completely. Your CPU will overheat within seconds to minutes depending on your workload. Most BIOS will trigger a thermal alarm and shut down your computer automatically to prevent damage. Do not do this intentionally.

Can I damage my fan by running it at 100% all the time?

Running at 100% will wear out the fan bearing faster than normal operation, but it takes years of continuous use to cause failure. A fan at 100% is loud and uses slightly more power, but it will not break your computer. Automatic mode is better because it only runs at high speed when needed.

Why does my fan speed keep changing even though I set it to manual?

Some BIOS settings override manual mode if the CPU gets too hot. This is a safety feature. If your fan is reverting to automatic despite your manual setting, your CPU is probably running hotter than you expect. Check the temperature and consider raising your manual speed setting or switching back to automatic.

Do I need to change fan speed if my computer is running fine?

No. If your CPU temperature is below 80°C during normal use and your computer is not too loud, automatic mode is already doing its job. Changing the fan speed will not make your computer faster or last longer.

Can I control the fan speed from Windows without going into BIOS?

Only if your motherboard or laptop manufacturer provides software for it. Windows itself does not have built-in fan control. Check your manufacturer's support website to see if they offer a control program for your specific model.