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What exactly is PWM PST?

PWM stands for "pulse width modulation." This is a standardized pulse signal that controls the fan speed. The "PST" in the product name identifies our popular PWM sharing technology, where the PWM signal from one fan is shared with other fans.

PWM_4_Pin_Illustration.jpg
  • Pin#1 is responsible for grounding on a 4-pin fan, while Pin#2 supplies power to the fan.
  • Pin#3 is responsible for returning the RPM to the motherboard.
  • Pin#4 passes the PWM signal to the fan.

The fourth pin of the PST adapter transmits the PWM signal to the other connected fans. In case of voltage control, the signal of the second pin determines the speed of the chained fans.

What are the advantages of PWM sharing technology?

  • Multiple fans can be connected and controlled via one connector on the motherboard.
  • Multiple fans can be controlled simultaneously via one fan curve.
  • Sharing technology also works with 3- and 2-pin fans with voltage control turned on.

What is the advantage of a customized fan curve?

PWM_PST_Curve

The user has the possibility to adjust the fan speed depending on the temperature. In this way, the volume can be limited at low loads and still ensure reliable cooling at high loads.

The PWM settings can be configured via a corresponding software or directly in the bios. You can choose from various presets or create a manual curve.

Detailed instructions on how to change your PWM settings can be found here:

Adjusting the PWM settings

How many fans can I connect in series via PWM PST?

How many fans can be operated on one header via PWM sharing technology depends on the output of the fan header and the maximum current of the fans in relation to the voltage. Motherboard fan headers typically have an output of 1 to 2 amps. You can find the specification of the amperage of the ARCTIC fans on the back of the motor hub as well as under the technical details.

There are a variety of fan connectors on a motherboard that can be used for connection. Among others these are:

  • CPU_FAN
  • CPU_OPT
  • CPU_PUMP | PUMP_FAN
  • AUX_FAN
  • SYS_FAN(1)
Motherboard Connector

For example: if a fan requires a maximum current of 0.2 amps and the motherboard fan connector supplies 1 amp, then up to 4 fans can be connected in series and operated via PWM PST.

In concrete terms: If we take a BioniX P120 (0,13 A) and a 1 Ampere motherboard connector, this results in 1 A / 0.13 A = 7.6 fans (hypothetical). It should be noted that there may be a voltage drop across the cable length, and the last fans may reduce in speed if the intended specification is exceeded. Therefore, never use more than 7 fans in series (in this example) - otherwise the motherboard may also be damaged.

Info: The exact specification of the current of the fan/pump header can be found in the manual or on the data sheet of the motherboard.

Notes on using the PST cable:

Four fans without PST technology can be connected in series using our PST Cable Rev. 2. Their speed will be synchronized, but only the speed of the first fan in the chain will be returned to the motherboard.

PST Cable

Using the ARCTIC Case Fan Hub:

Case Fan Hub connected Fans

Parallel control of multiple fans per port is possible with ARCTIC's Case Fan Hub. It is specified for a maximum output power of 1 A per port.

The power supply of the Case FanHub via SATA power is specified with 4.5 A. Therefore, all ports should never be loaded with 1 A at the same time! Nevertheless, PST operation is also possible on individual ports of the Case FanHub.

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