Should I power off the PSU or the MB for case fans?

[Wedge]

What's the advantage or disadvantage of connecting case fans to the motherboard, rather than the cables running from the Power Supply?

[Nunyobiznes]

You can monitor fan speed if they are connected to a MB that supports monitoring. That's about the only difference I can think of.

[LTR12101B]

Just don't power a Delta case fan off the motherboard, they draw too much power.

Monitoring, and tidyness, are the main advantage.

For the CPU fan, many BIOSes also have an option to alarm or shutdown on fan fail - this is not normally extended to the other fan positions, and is one reason for making sure that you put the CPU fan on the right one.

[Coaster]

@ Wedge,

If your MotherBoard has fan monitoring function you can use a “special adapter” that allows you connect you fan to the MotherBoard for monitoring but provides power from the power supply. This adapter provides the best of two worlds.

To acquire information about this “special adapter” refer to the below link.

h**p://www.directron.com/3splitter.html

I have used this “special adapter” on a couple Computers and I am very pleased with the results.

Also if you ever find that your Case Fans make too much noise there is also another “special adapter” that reduces Case Fan voltages thus reducing fan noise.

You can acquire information about this “adapter” at the provided link.

h**p://store.yahoo.com/directron/12to7.html

Regards,
Coaster

[Wedge]

Great Coaster!

It just so happens that I was looking for these items because I'm adding fan #2 (has to be an 80mm) to my case and I want to keep it quiet and monitor rpms if the fan supports it.

What about this Noise-Reduction Washer? Do you know if it helps reduce fan noise?

[LTR12101B]

See also
http://www.7volts.com/

Quite a nice site - or if you do electronics, this link I picked up in a newsgroup.
http://www.junkroom.freeserve.co.uk/fanspeed.htm

How much would the big guns charge for one of those? - dunno if the temperature compensated idea would work though!

[Wedge]

@LTR12101B, Great links!

After reviewing 7volt.com I am starting to think that maybe my PSU generates most of the noise I am hearing. The article speaks highly of the Seasonic PSU for silence.

Does anybody know who currently makes the quietest PSU available?

[jorel]

Originally posted by Coaster
@ Wedge,

If your MotherBoard has fan monitoring function you can use a “special adapter” that allows you connect you fan to the MotherBoard for monitoring but provides power from the power supply. This adapter provides the best of two worlds.

To acquire information about this “special adapter” refer to the below link.

h**p://www.directron.com/3splitter.html

I have used this “special adapter” on a couple Computers and I am very pleased with the results.

Also if you ever find that your Case Fans make too much noise there is also another “special adapter” that reduces Case Fan voltages thus reducing fan noise.

You can acquire information about this “adapter” at the provided link.

h**p://store.yahoo.com/directron/12to7.html

Regards,
Coaster

great ..or better,perfect observations Coaster
"If your MotherBoard has fan monitoring function you can use a “special adapter” that allows you connect you fan to the MotherBoard for monitoring but provides power from the power supply. This adapter provides the best of two worlds."

don't need to say more.

[LTR12101B]

I would also add that you CANNOT use fan monitoring with the 7 volt hookup, as it raises the fan's 0v level to 5 volts.

Some motherboards allow fan control through the onboard positions - software such as
http://www.almico.com/speedfan.php
Lets you vary the speed of certain fans in response to certain temperatures.

Implementation of this feature is patchy though!


"Noisekiller" power supplies often have a thermal fan solution internally.
If combined with one of the heatsinks with a thermal fan, and low speed case fans, you can make a relatively quiet system.

The low cost Q-Tec PSU range includes "low noise" models, but a well reviewed brand would probably be a better choice.