Feb 7, 2010
hi there,

i have a pretty generic case but i forgot the brand of it....
some of the fans on the the case are super loud and i want know
if i can change the rpm of them

the fans connect to the psu and not the 3/4 pin to mobo....
are my fans just bad or can i slow them down?
Either you buy a fan controller, either you so some tweaking.

Shut down the computer and unplug it. You must swap the cables in you molex so you'll have the red wire from the fan's connector corresponding not with the yellow wire on the molex but with the red one. You need a small flat screwdriver.

So, you must have red+black instead of yellow+black.

That will reduce the fan speed but also will increase the temperature in your PC.

Or buy some better fans.

You can't change the RPMs. Not unless they have a switch...

Then again, I guess you would wire up some resistors. Of course, I have no experience doing that with a power supply.
Here's what I would do:

• I think maybe a 1K-3K ohm resistor should be able to slow the fans enough. Basically adding the resistor to the circuit will take some of the voltage off of the fan and put it on the resistor instead.
• More voltage across the resistor= less across the fan=slower fanspeed. The greater the resistor size in ohms, the more voltage will be across the resistor. V=IR therefore increasing R (resistance) will increase V, the voltage.
• Play with wires. I think the best way would be to get an add-on for the end of the molex connector (I am assuming they run on a molex connector) and just cut it off so you can see the wires. Look at the original two connectors and figure out which two wires are used to power the fan. Strip the ends. Cut and strip the ends of the wires attached to the fan also.
• Solder one end of the resistor onto one of the wires. Solder the other to the fan wire. Do the same with the second but do not add a resistor. Make sure they are the same as they were before. If you swap the wires then the fan will blow backwards lol.
• Insulate each exposed part with something. Some electrical tape should be fine.
• And bam, you are done
• If you are more ambitious, I suppose you could rig up 3 or more wire sizes and a switch to be able to vary the speed of your fan by changing which resistor is in the circuit.
Of course, a slightly more expensive solution would be to buy quieter fans. But that’s no fun since the setup would take like 5 seconds. :)
Fan noise comes primarily from running at high rpm's. Under 1000 rpm is normally quiet.

Smaller fans like 80mm need to run at 2000 rpm or more to move air.
That is why 120mm fans are preferred, and even 140 or 200mm fans are better.

If you have adequate cooling and want to reduce fan noise, I suggest the zalman fanmate:

What case do you have? What size fans do you have?


Feb 7, 2010
what enzo said sounds nawrly haha.....
i totally forgot my case manufacture but its mid tower and all my fans are 80 and one is 120

how does the fan mate work??? can you hook up multiple fans to it?

I may have misled you. The fanmate is for fans with 3 wire fan connectors, not 4 wire molex connectors. It works by reducing the voltage from 12v continuously down to 5v which is the minimum that most fans need to start.

A similar device that would work with molex connectors is this one:

If you are handy, you can rewire your molex connectors to get 7v or 5v.

Really, though, if you have a case with 80mm fans, consider replacing it.
Consider the Antec 200 for $49.99 delivered: