The program

Speedfan is currently available in the final version 4.50 and can be downloaded from the author’s site or here on CB.

With supported motherboards, the program gives control over all adjustable fan connections. Both the minimum and maximum speed can be set. In addition, the control speed can be specified. Since the full 12V are applied briefly at startup, fans with a high starting voltage can also be used.

The first settings

After Speedfan is installed and started for the first time, there is absolute chaos. None of the fans is adjustable and the temperature and voltage values do not seem to be correct either. Now a preselection has to be made. To do this, click on Configure ->Options in the upper right corner and set the language to German for the first time.

Using Everest, your mainboard’s monitoring tool or simply monitoring under different load conditions, you can clearly assign the temperatures and rename them accordingly under Configure ->Temperatures, which is best done with the F2 key in all menus. In my case, the 13°C is the CPU and 39°C is the sensor for the case.Hdd0 should be as clear as Core1 and Core2. temp 3 is a measurement error in my system and therefore the check mark comes out and is no longer displayed in the main window.

Under “Fan” you can remove the values that should not be displayed or controlled and rename the fans directly on this occasion.

The same is true for tensions. Values that are not interesting or obviously wrong can be checked off.


Now the first hurdle has been cleared and Speedfan delivers usable data.

Automatic fan control

To allow Speedfan to control the fans you need to go to the Custom Settings menu. In case of my 965P-DS3, I have to select IT8718F in the upper field. After clicking on the option “PWM1 mode” etc., the system switches to “Software controlled” at the bottom of the “Apply to” field and confirms with a tick in the “Remember” field. This transfers the control of the fans to Speedfan. The point “SmartGuardian” is also called differently by other mainboard manufacturers, but this does not change the setting.

When you return to the main window you can manually control the fans. Now the respective fans have to be assigned to the individual temperatures. To do this, go to the “Temperatures” menu. Since we have already renamed the individual temperatures, we only need to check the corresponding box. Make sure that only one temperature for one fan takes over the control.

Now we go to the tab “Speeds” where the field “Automatic variation” is activated.

If you now switch back to the main window and tick the box “Automatic fan speed”, automatic control takes effect. Up to now, all this does not differ from the many explanations to Speedfan which I have already found on the net.

But what have we achieved so far?

Under load, which is best generated with Prime 95, the temperature curve of the integrated monitoring tool looks like the Swiss Alps. The speed curve of the Cpu fan is in no way inferior to this. The case fan also adds its mustard at regular intervals. The resulting background noise is correspondingly annoying.

So let’s get to the fine-tuning.

Fine tuning

The following steps depend to a large extent on the installed cooling hardware and your personal limits. Accordingly, it is a little more time-consuming. The first steps are best done with the case open so that you can watch the fans. By default, Speedfan controls in 10% steps. After a few tries, the finest subdivision of 1% turned out to be ideal. These are set under “Options ->Delta value for the fan speed”. While we are here, there is also a check box in the “100% performance when closing the program”, in the “start minimized” and the “minimize when closing” field.

Normally Speedfan controls in the range of 0-100%, but in order to achieve a quiet and even cooling without speed peaks, the fans should never stop because even the best fan always needs a certain starting voltage. My case fan, for example, starts at 72% with 650 rpm and rotates at 85% but with almost 1000 rpm. On its way down, however, it runs up to 68% or 370 rpm. So I set the minimum speed to 68% and the maximum to 80%, which is max. 800 revolutions at the peak.

The same applies to the CPU fan, but this time under load with Prime 95, you can set the maximum and minimum speed according to your own preferences and the technical specifications of your hardware. You must also specify a “desirable” temperature. My personal pain limit for the coretemp is 62°C. As an emergency anchor for warm days or special operating conditions, a “warning temperature” can be set in the menu for the temperatures at which the corresponding fan goes to 100% regardless of the settings and thus prevents the hardware from dying out. In the idle, the lowest possible speed should suffice, but as always this can be found out by trial and error and varies depending on the hardware installed. And here’s the reward for working under Prime.

And in idle mode

What else is there

Unfortunately, there is no autostart option in Speedfan, but this problem can easily be fixed by linking the start file in the autostart folder. If temperatures are obviously displayed incorrectly, they can be corrected up or down under “Custom->Temperature offset”. Furthermore, Speedfan offers a monitoring tool under the point “Graphs” which records the course of all fan speeds, voltages, and temperatures of the last half hour. The temperature of Nvidia maps is also displayed. This means that a fan mounted on an Accelero S1, for example, can be controlled depending on temperature. A few overclocking options can be found under “Bar”. However, this option has not been extended since socket A. You can download finished profiles for Speedfan under “Information->get config”. As I myself have already experienced, some of them are to be enjoyed with caution, as they are only created by private individuals.


My AC Freezer is not the strongest cooler and always works under load with the mainboard control at the limit. Since Speedfan allows a control of the fans exactly tuned to the own hardware, it is possible to create a quiet but at the same time a fast computer by targeted undervolting in connection with OC also with standard hardware.