How to reduce server power supply fan noise?

We dubber a server we installed in 2007 "Concorde" because of the noise it made and the wind,

or connect the power leads to +5 instead of +12, IME fans still run on

If it's a normal pc fan it's looking for an open collector, giving pulses on the yellow wire one pulse per cycle of the fan motor and ground being the black wire.

You could solve this with a 555 or go all out and make a PLL to multiply the speed.

yeah, but this is a 1U server so it needs a low profile powersupply, an ATX powersupply won't fit.

You'll need an (electrically) insulated cooler for the PSU, the tabs on the switching transistors are live, usually the heatsink is too.

Yep, I have an MDF & foam box I wrapped a 1U server in a long time ago since it was too darn loud even in a closet. Basically an S with the server in the middle, it knocked off enough of the irritating high-frequency noise to make the thing bearable.

But.

The best solution by far is to ditch the rack server and buy a tower server - those are often actually optimized for sound and power consumption while rack servers basically never are. In many cases the power bills (especially if you run AC part of the year and they also add to your cooling load) from an old rack server will rather quickly exceed the cost of an equivalent-computing-power tower server.

That didn't happen to be an option for the 1U server I built the box for

- but whenever it is an option, it's the better option, unless you are in fact trying to cram all the computer power you can into the minimum amount of space, and are happy to pay for the resulting power and cooling (more power) costs, and don't care how loud the server room is. In which case you won't be buying legacy servers, you'd be selling them off...

Thanks. And the blue wire is control. It ranges from 1.65 to at least 5 V.

Using the fan output supply pins for V+ and ground, that sounds easiest.

Then a large fan can be funneled to the power supply. I just need to satisfy/disable those power supply fan inputs.

Nope. Apparently four pin fan speed is controlled by the blue wire that ranges from 1.65 to over 5 V. The red V+ wire remains 12 V.

But I can try by connecting those two fans to a 5 V supply with their signal pins heading back to the power supply. Later.

Why do you not try a simple google search, ya dopey f*ck?

It took me exactly ten seconds.

Brainless blunder

Looking at the two 3 pin fan connectors on the lower left.

The leftmost connector.

From right to left.

Black is ground. Red is 12 V. Apparently yellow is the return signal wire.

The right connector.

Same orientation, from right to left.

Gray is ground. Orange is 12 V. Apparently purple is the return signal wire.

It is zero to 3.3 volts PWM.

Finding info about four conductor fans was a simple google search.

Don't look for pages to visit look for images and see a whole page full of schematics, explanations, links, etc.

Sheesh.

Try, try, try. If you tried to get pertinent info first, you might succeed in your goal.

You take pathetic to an all new low.

Using 5 V (as someone suggested) works. Very quiet, could be higher voltage (if there were some intermediate supply voltage between 5 and 12 V).

Simple to test.

Just cut the two fan-connector V+ wires (see the picture and description below) and connect the fan side of those wires to a 5 V floppy power connector. Leaving the ground and signal wires untouched and connected.

So, Yes, all that matters is the power supply fan feedback signal be present. Doesn't require the fan spinning at full 12 V speed. I guess it's just that cheap, thankfully.

Should work while my room is cool, at least long for my purpose. I'll regularly test the air (temperature) coming out of it.

OF COURSE THIS ISN'T WHAT IT WAS DESIGNED FOR AND COULD CAUSE A FIRE.

Don't try this at home.

Anything but the right way, eh?

Yeranidiot.

DecadentLinuxUserNumeroUno wrote in news:n99t43$v7s$1 gioia.aioe.org:

Same exact nym for three years, retarded crossposting Usenet dumbfuck.

Probably not, as long as you don't slow them down too much. I usually put a couple diodes in series with the +5 or +12 V wire, that drops the speed a bit.

Jon

Already proved, the feedback is acceptable to the power supply even when the fan is powered by only 5 V (down from 12).

Right. I'd like it higher than 5 V, and I guess that will do it.

I have figured it out , what I id was take an older fan with way bigger bl ade ,, I did a little fan mod I put the bigger lade on the little psu fan a nd like magic works perfectly. but keep in mind you do still need to keep t he psu cooled, so just mount anouther fan on the psu with the case open . m ake it fit.