quick fan question

fuzzfactory · 06-28-2008, 01:06 AM

hello everyone, this is my first post so bear with me if i made any mistakes:)

i just installed a cpu fan on my computer, and it alternates between going really fast to slowing down, then fast again, then slowing down again, etcetc.

it came with a 4-pin power connector, but my mobo only has a 3-pin socket for the cpu fan. i just plugged the 4-pin into the 3-pin socket... is this bad? is this why its doing the weird alternating thing? my computer is cooled just fine and everything is running smoothly, just the fan speeding up and slowing down all the time gets annoying.

thanks for any help!

magnethead · 06-29-2008, 07:39 PM

4 pin is Pulse width modulated while 3 pin is voltage modulated. If it is surging heavily, just go into bios is disable CPU fan speed control. If it changes speed smoothly, that's the motherboard doing what it knows to do. Either way, I'd advise disabling CPU fan control if you can stand the noise. On my computer, i have the stock intel cooler and i cant hear it at full 2300 RPM.

06-28-2008, 01:06 AM	#1 (permalink)
fuzzfactory Registered User Join Date: Jun 2008 Posts: 1 OS: xp SP2	quick fan question hello everyone, this is my first post so bear with me if i made any mistakes:) i just installed a cpu fan on my computer, and it alternates between going really fast to slowing down, then fast again, then slowing down again, etcetc. it came with a 4-pin power connector, but my mobo only has a 3-pin socket for the cpu fan. i just plugged the 4-pin into the 3-pin socket... is this bad? is this why its doing the weird alternating thing? my computer is cooled just fine and everything is running smoothly, just the fan speeding up and slowing down all the time gets annoying. thanks for any help!

06-29-2008, 07:39 PM	#2 (permalink)
magnethead Tech Hardware Team Join Date: Mar 2006 Location: TX Posts: 2,121 OS: XPH, 2K My System Blog Entries: 2	Re: quick fan question 4 pin is Pulse width modulated while 3 pin is voltage modulated. If it is surging heavily, just go into bios is disable CPU fan speed control. If it changes speed smoothly, that's the motherboard doing what it knows to do. Either way, I'd advise disabling CPU fan control if you can stand the noise. On my computer, i have the stock intel cooler and i cant hear it at full 2300 RPM. __________________ For proper support: what are you running? video card, cpu, m/board, ram, power supply, brand, wattage, any error message? PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER