bilboe

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Hi everyone!
A few months ago, I put together a build with 3 case fans: 1 LED, and 2 normal; all of which are plugged directly into the PSU.
However, I have noticed that the primary source of sound in the computer are the fans, so I would like to plug them into the motherboard. Will this make them automatically slow down and speed up based on temperatures? Is there a setting in the BIOS to enable this? If I plug the LED fan into the motherboard, will it still be at full brightness?

Thanks!

Bilboe
 

Axeon

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Yes the LED fan will still be the same brightness, but no it won't spin faster and move more air if something gets hotter because they have no built in heat monitor. You could do this buy using a program however to adjust fan speeds, something like SpeedFan 4.37 would work. Or you could always use the fan controller in your drive bay.
 

bilboe

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So then would it be any use to plug the fans into the motherboard? Is a fan controller worth the investment?
 
What are your complete computer specs? Some motherboards do in fact have fan headers that can vary the fan speed based on temp. My 2 year old Gigabyte board has one 4-pin system fan header that works that way. Does your motherboard have any 4-pin fan headers other than the CPU fan one?
 

bilboe

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Im not sure, its a gigabyte EP45-UD3P.
 

bilboe

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UPDATE: from gigabytes website:
# 1 x CPU fan header
# 2 x system fan headers
# 1 x power fan header

Which is which?
 
Yes, that motherboard has one 4-pin fan header labeled SYS_FAN2 located by the purple SATA ports that should vary fan speed. What kind of fans do you have? Can they even be plugged into a motherboard fan header? You could swap out the fans for quiet low-RPM models and save the hassle.

Scythe SY1225SL12M 120mm "Slipstream" Case Fan - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835185058 $8.99

That fan spins at 1200 RPM even with a full 12v (plugged directly into the PSU), moves 68.54 CFM, and only generates 24.00 dBA (pretty much silent).
 

bilboe

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My fans came with my case, and are rated at 21 dba.
 

bilboe

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Oh, sorry. Its a Cooler Master 690.
 
The fans that come with the 690 are already pretty quiet. According to this review, yes, the fans should be a little quieter when plugged directly into the motherboard:

http://www.techpowerup.com/reviews/CoolerMaster/RC_690/5.html

Here's a quote from the review: "The fans emit a clean "wooshing" sound if connected directly to the power supply, but are nearly silent when plugged in directly into the mainboard."

If that still isn't quiet enough for you then pick up a fan controller. 1200 RPM is already pretty slow, though. You won't be able to slow them down a whole lot without sacrificing cooling capability.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=zalman+fan+controller&x=0&y=0

The Zalman Fan Mate 2 would be a cheap way to slow down the fans.