How to change CPU fan speed without bios in just 5 minutes? - Reedablez

The CPU fan keeps your computer's central processing unit (CPU) cool and functioning optimally. While the BIOS (Basic Input/Output System) typically allows you to control the fan speed, sometimes it may not offer the level of customization you desire. Sometimes, you might not even have access to the BIOS settings.

To change CPU fan speed without accessing the BIOS, use software solutions like SpeedFan, HWiNFO, or Open Hardware Monitor. These programs allow you to customize fan profiles, adjust fan speeds, and monitor temperatures. Additionally, you can use hardware methods like fan controllers or resistor-based voltage control for manual fan speed adjustments.

This comprehensive guide will walk you through various methods to change your CPU fan speed without relying on the BIOS.

Why Adjust CPU Fan Speed?

Before delving into the methods, it's essential to understand why you might want to adjust your CPU fan speed. Here are a few common reasons:

Noise Reduction: Reducing the fan speed can lead to a quieter system, which is especially desirable if you use your computer for tasks that don't require maximum cooling.

Energy Efficiency: Lowering the fan speed can save energy and reduce power consumption, which is beneficial for laptops and desktops running on battery or aiming for energy efficiency.

Prolonging Fan Lifespan: Slowing down the fan can extend its lifespan, reducing wear and tear. This is important for systems in continuous use.

Custom Cooling Solutions: Fine-tuning the fan speed allows customized solutions tailored to your needs, such as overclocking or maximizing cooling during resource-intensive tasks.

Software-Based Fan Control

You can rely on software-based fan control solutions to change your CPU fan speed without accessing the BIOS. These applications allow you to adjust fan speeds, monitor temperatures, and customize fan profiles. Here are some popular software options:

1. SpeedFan

SpeedFan is a widely used, free software utility for monitoring and controlling fan speeds and temperatures. It's compatible with various hardware and allows you to create custom fan profiles based on temperature readings. It provides a high level of control, but it may require some configuration.


HWiNFO is a comprehensive system monitoring and reporting tool with fan control features. It provides detailed information about your system's components, including CPU and GPU temperatures, and allows you to customize fan speed profiles.

3. Open Hardware Monitor

Open Hardware Monitor is an open-source software that provides real-time temperature and fan speed monitoring. While it doesn't offer advanced fan control features like SpeedFan, it can be helpful for monitoring and basic adjustments.

4. NoteBook FanControl

If you're using a laptop and want to control the laptop's fan speed, NoteBook FanControl is a specialized utility that works with many laptop models. It allows you to adjust fan speed to balance cooling and noise.

Manual Fan Speed Adjustment

In addition to using software-based solutions, there are manual methods to change CPU fan speed without BIOS access. These methods are more hardware-oriented and require additional components.

1. Fan Controller Hardware

A fan controller is a hardware device that allows you to adjust fan speeds manually. It typically connects between the fans and the power source. Some controllers come with knobs or sliders for precise adjustments. These are more commonly used in custom PC builds or modifications.

2. Resistor-Based Voltage Control

If you want to reduce the fan speed without a dedicated fan controller, you can use resistors to lower the voltage supplied to the fan. By inserting resistors in line with the fan's power source, you can decrease the voltage and reduce the fan speed. This method is more suitable for advanced users with knowledge of electronics.

Important Considerations

When changing your CPU fan speed through software or hardware means, there are some key considerations to keep in mind:

1. Compatibility

Ensure that your software or hardware is compatible with your system's components. Some solutions work better with specific hardware configurations.

2. Monitoring

Constantly monitor your CPU temperatures when adjusting fan speeds. Overheating can lead to system instability and damage. Software utilities often include temperature monitoring features.

3. Balancing Cooling and Noise

Finding the right balance between cooling and noise is crucial. Reducing fan speed might make your system quieter, but it should not compromise cooling to the extent that it affects performance or damages your components.

4. Custom Profiles

Consider creating custom fan profiles that adjust fan speeds based on temperature. This ensures that the fan responds appropriately to changes in system heat.

5. Testing and Tweaking

Changing fan speeds can be a trial-and-error process. Test your settings and observe the impact on both temperatures and noise. Adjust as needed.

6. Backup and Restore Defaults

Before making any changes, note or document the default fan settings. This way, you can revert to the original configuration if needed.


  • While adjusting your CPU fan speed without BIOS access is possible, it's essential to take precautions to avoid potential issues:
  • Avoid Extreme Settings: Don't set the fan speed too low, which can lead to overheating. Ensure there's adequate cooling for your CPU.
  • Monitor Regularly: Monitor your system's temperature and fan speeds to detect unusual behavior or potential issues.
  • Backup Your Data: If something goes wrong or adjustments cause instability, back up your data to prevent data loss.
  • Don't Overwork the Fan: While reducing the fan speed is beneficial, don't force the fan to work beyond its capacity. Maintain a balance between cooling and noise.

How do I manually change the CPU fan speed without using software?

Manually changing the CPU fan speed without using software typically involves hardware-based solutions. While not as common as software methods, manual adjustments can be helpful, especially when you want direct control over your fan speed. Below, we'll explore two manual ways to change CPU fan speed: a fan controller and a resistor-based voltage control.

Method 1: Fan Controller

A fan controller is a dedicated hardware device that allows you to adjust fan speeds manually. These controllers come in various forms, from simple knobs or sliders to more advanced digital interfaces. The basic concept remains the same: you connect your CPU fan to the controller, and then you can increase or decrease the fan speed as desired.

Here's how to manually change CPU fan speed using a fan controller:

1. Acquire a Fan Controller

Purchase a fan controller that suits your needs and is compatible with your fan and system. Ensure it provides sufficient control options for your requirements.

2. Install the Fan Controller

Open your computer case and install the fan controller in an accessible and secure location, preferably close to the CPU fan. Secure it in a vacant drive bay or find a suitable place inside the case.

3. Connect the CPU Fan

Unplug the CPU fan from the motherboard's CPU fan header. Instead, connect it to the corresponding fan port on the fan controller. This step may require using extension cables or adapters to reach the controller.

4. Connect Power

Most fan controllers require Power through a Molex or SATA power connector from your power supply unit (PSU). Ensure the controller has the necessary power source.

5. Adjust Fan Speed

Turn on your computer and access the fan controller. Depending on the controller type, you can manually adjust the fan speed using knobs, sliders, or a digital interface. Increase or decrease the fan speed according to your needs.

6. Monitor Temperatures

As you adjust the fan speed, monitor your CPU temperatures. Some controllers provide temperature sensors to help you gauge the impact of the speed changes. Ensure that the temperatures remain within safe limits.

7. Fine-tune and Test

Experiment with different fan speeds to find the right balance between cooling and noise. Ensure the system remains stable and calm during demanding tasks.

Method 2: Resistor-Based Voltage Control

Resistor-based voltage control is a more DIY method of changing CPU fan speed. It involves introducing resistors into the fan's power supply circuit to lower the voltage and reduce the fan's speed. While this method requires some electronics knowledge and soldering skills, it can be cost-effective.

Here's how to manually change CPU fan speed using resistor-based voltage control:

1. Gather the Materials

You'll need resistors with appropriate resistance values, a soldering iron, solder, heat shrink tubing, and wire strippers.

2. Identify the Fan Wires

Identify the fan's positive (usually red) and negative (usually black) wires. The third wire, often yellow, is used for monitoring and can be left unchanged.

3. Calculate Resistor Value

Determine the resistance value you need to achieve the desired fan speed. This may require some experimentation, as the relationship between resistance and fan speed is not linear.

4. Solder the Resistor

Cut the fan's positive wire and strip the ends. Solder one end of the resistor to one cut wire end and solder the other end of the resistor to the other cut wire end. This will introduce the resistor into the circuit, lowering the voltage.

5. Insulate with Heat Shrink Tubing

Slide heat shrink tubing over the soldered connections and use a heat source (like a heat gun) to shrink the tubing and insulate the connection.

6. Test and Adjust

Reconnect the fan to your power source and turn on your computer. Monitor the fan speed and the effect on CPU temperatures. Adjust the resistor value to achieve the desired fan speed and cooling performance.

7. Ensure Stability

Make sure your system remains stable and does not overheat during demanding tasks. Fine-tune the resistor value if needed.


Software-based solutions or hardware components can change your CPU fan speed without BIOS access. Whether you aim to reduce noise, save energy, or customize your cooling solutions, options are available to suit your needs. However, it's crucial to exercise caution, monitor your system's temperature, and find the right balance between cooling and noise. By taking the appropriate precautions and making informed adjustments, you can effectively manage your CPU fan speed to optimize your computing experience.

Frequently Asked Questions

Why would I change my CPU fan speed without accessing the BIOS?

Changing the CPU fan speed without BIOS access can help reduce noise, save energy, customize cooling, or compensate for limited BIOS control on some systems.

How can I use software to change the CPU fan speed?

Install the desired software and configure fan profiles or adjust fan speeds within the application. These programs provide user-friendly interfaces to control fan speeds.

Are hardware-based methods for changing fan speed suitable for beginners?

Hardware methods, like fan controllers and resistor-based voltage control, may require some technical knowledge and hardware adjustments. More advanced users often prefer them.

What should I consider when adjusting my CPU fan speed manually?

Consider factors like compatibility, temperature monitoring, balancing cooling and noise, creating custom profiles, testing settings, and having a backup of default configurations.

Are there any risks to changing CPU fan speed without BIOS access?

Risks include overheating if fan speed is set too low, potential hardware incompatibility, and data loss if your system becomes unstable due to incorrect settings. Monitoring and careful adjustments are essential.

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