Question can i control the speed of my case fans even if they are connected through the power supply?


Oct 10, 2019
SpeedFan is popular, however it hasn't been updated for a number of years, and I ran into problems with SpeedFan as it was not able to read the sensor chip on my current motherboard.

If the fans are connected to your PSU alone, I don't see how it would be possible to control them using softare.

If the other fans are actually connected to the motherboard or a fan controller, but you are just not able to control them, I'll recommend trying Argus Monitor

It is free for 30 days with full acces to all features. It does require some setting up, to get the most out of it. You will quickly be able to see if it works though.
Personally I find it very usefull and don't really have much negatives to mention

You could try to install it, and see if that program is able to read the sensor chip on your motherbord, if it is less than 4 years old, it could be a possible solution.

But again, if the fans are not actually connected to the motherboard, I don't believe you will be able to use software control, although I can't definately rule it out
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To your headline question: No.

The power provided from your PSU directly to any fan is only a fixed 12 VDC with no method of changing the fan speeds, and not even any way for it to read the fan's speed signal.

Control of a fan's speed commonly is done by the motherboard. For that it has fan headers for two different functions - CPU cooling, and case cooling. The ones for the CPU are guided by a temperature sensor inside your CPU chip; the ones for case fans are guided by a different sensor on the mobo. They may use one of two common methods of changing fan speeds: the older Voltage Control Mode can reduce the supplied voltage to reduce fan speed; the newer PWM Mode sends a special PWM signal to 4-pin fans designed to use that signal to change fan speed. Both fan types send their speed signals back to the mobo header where they can be counted and displayed, and used to detect failure of a fan. Unless you plug your fan into one of these mobo headers with these features, you have no control over fan speed.

You can buy and install third-party fan speed control modules to let you do some of this speed control yourself manually, but using the headers available on all mobs is easier and cheaper, and usually better.

Speedfan is only a software utility that can read info from the mobo and change some settings in the mobo BIOS system to make it easy to do some of the fan control tasks. Your mobo VERY likely also came with software for a similar purpose on its CD of utilities and drivers. Neither of those tools can do anything at all to modify what a PSU does.