PWM vs Non-PWM Fans

As an expert on cooling and cooling options, I’ve seen some significant distinctions among the PWM (Pulse Width Modulation) as well as Non-PWM (DC Voltage Control) fans, both of which affect the performance of your system and efficiency in different ways. Below is an in-depth explanation of these distinctions:
1. Control Accuracy

• PWM Fan:
  • Control Mechanism Fans that use PWM have a 4-pin connector. the fourth pin supplies the PWM signal, which changes the duration of the duty cycle to adjust the speed of the fan. This enables exact adjustment of speed.
  • PWM fans can alter speeds at a rate of up to 2256 levels of control which allows them to run with a minimum of 10 percent of their maximum speed.
• Non-PWM Fans:
  • Control Mechanism Non-PWM fans have 3 pins for connectors that allow control of speed via voltage adjustments. By lowering the voltage, you can reduce the speed of the fan, however the control may be less precise.
  • Non-PWM fans generally have fewer speeds and work within a range of 30 to 100 percent of their speed maximum.
• Examples: In a high-performance gaming computer, PWM fans allow for custom-tuned cooling which reacts rapidly to changes in temperature and maintains the highest performance while minimizing sound. Fans that are not PWM, in contrast, could be unable to add the same degree of responsiveness and efficiency.
• NOTE: Precision control with PWM fans could cut down on system noise by as much as 40% when in comparison to non-PWM fans with similar temperature levels.

2. Efficiency and Performance

• PWM fans:
  • Effectiveness: PWM fans are made to run more effectively by altering the speed to temperature demands. They can raise their speed at high speeds as required while reducing to lower speed, thereby conserving energy as well as lessening noise if full cooling is not necessary.
  • PWM fans could help save as much as 20% on energy usage in comparison to non-PWM fans who are operating at lower speeds.
• Non-PWM Fans:
  • Performance: Non-PWM fans generally work at a constant voltage. This means lesser flexibility and use of energy because they are not able to change their speed dynamically based on the temperature.
  • Non-PWM fans may use as much as 15% more energy at slower speeds than PWM fans due to their less effective control of the speed.
• Examples: In a system that has a variety of demands, like the workstation that’s used for rendering and gaming, PWM fans adjust their speed under the demands of the system, resulting in greater efficiency overall and better efficiency.
• Notice: Efficiency gains with PWM fans may translate to a reduction of power consumption of around 15 to 20 percent when mixed-use situations are involved.

3. Noise Levels:

• PWM Fan:
  • Noise Management PWM fans are typically quieter as they run at lower speeds when the temperature of the system is controlled thereby reducing the noise.
  • PWM fans are typically 25% to 30% quieter when operating at lower speeds when compared with non-PWM fans because of their capacity to operate at lower RPMs with greater consistency.
• Non-PWM Fans:
  • Noise Management Fans that are not PWM tend to generate more sound when operating at lower speeds because they are typically running at a constant speed, and need higher RPMs in order to complete sufficient cooling.
  • Non-PWM fans are as much as 30% louder when compared with PWM fans running at slower speeds.
• Examples: In a quiet office, PWM fans are preferred because they reduce noise when under different loads, as compared with noisy non-PWM fans.
• NOTE: PWM fans can cut down on system noise by up 30 percent in situations that require variable cooling. This makes PWM fans ideal for noisy environments.

4. Complexity and cost:

• PWM fans:
  • Price: PWM fans are typically more costly due to the advanced control system as well as extra parts.
  • PWM fans usually cost between 20 and 40 percentage more than other fans.
• Non-PWM Fans:
  • cost: Non-PWM fans are much less costly and have a simpler construction, making them an affordable feature to meet the basic requirements of cooling.
  • Non-PWM fans are about 20%-30% less than PWM fans.
• Examples: For budget-conscious builds with a focus on noise and precision control are not as important Non-PWM fans can be the most cost-effective solution.
• Notice: The cost difference implies that PWM fans could be 20-40 percent more expensive. However, they provide significant advantages in terms of performance and noise reduction.
• For more details in depth read this Why Motherboard Does Not Control PWM Fans?