I have a video card that is loud while idle, because the fan curve appears to be set rather aggressively. Unfortunately, this can not be changed via software.

The fan is connected with a regular 4-pin PWM header (black, red, yellow, blue).

I have some low-ohmage resistors (20-40 Ohms) and would like to try to limit the voltage supplied to the fan to find out if it solves the issue.

Normally, such adapters are available for 3-pin fans with a resistor on the positive lead. However, I am unsure if the same is possible with a PWM-controlled fan.


closed as off-topic by Chris Stratton, brhans, Elliot Alderson, Charles Cowie, Oleg Mazurov Sep 4 at 0:31

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – Chris Stratton, brhans, Elliot Alderson, Charles Cowie, Oleg Mazurov
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    \$\begingroup\$ The problem with this question is that you are asking someone to guess the behavior of an undocumented product. That makes it off topic here. It might be on topic on a PC hardware site, where existing knowledge of fans of this type would be possible. Here, it fails for lack of engineering documentation. \$\endgroup\$ – Chris Stratton Sep 3 at 21:28
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    \$\begingroup\$ I agree the comment about asking the question in wrong place but I will say don't tinker with graphic card , you can use MSI afterburner software "if your graphic card have fan control " otherwise just change the fan or if it's small one change it with passive cooler \$\endgroup\$ – Mordecai Sep 3 at 21:34

When a PWM fan doesn’t have a chop signal being fed to it, it functions exactly like a 3-wire fan.

So, sure, try the resistor drop. Not guaranteeing it will work but it’s worth a shot. It won’t damage the fan in any event. It may cause your GPU to overheat though, so use with caution.

Your motherboard may have spare fan plugs that do have PWM control that you can set with your BIOS. If you have a spare that could drive your GPU fans.

  • \$\begingroup\$ Most of motherboard's Bios doesn't have GPU fan control but if you plug the GPU's fan into motherboard you can adjust it by case fan but I don't recommended it because GPU fan depends on usage and most of the motherboard fan output don't gave enough power \$\endgroup\$ – Mordecai Sep 3 at 21:38
  • \$\begingroup\$ I planned on just cutting the positive lead and adding a resistor in between, I wasn't going to remove the PWM signal or speed meter leads. This way, I assume, the fan would just get less power supplied and spin slower, but still have PWM control. Is there an error in that logic? \$\endgroup\$ – Prototype700 Sep 3 at 22:18
  • \$\begingroup\$ No, it will work. But be mindful of what your GPU needs: do try to get the board's actual fan driver if possible. \$\endgroup\$ – hacktastical Sep 3 at 22:34
  • \$\begingroup\$ It will work but don't forget fan spins for a reason if you limit the fan speed it can burn your GPU , also adding resistor will cause control issues because GPU's system depends on temperature. Also don't forget resistor will heat too \$\endgroup\$ – Mordecai Sep 4 at 0:38

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