Quiet power supply - what wattage?

doodyrh · Post by **doodyrh** » Thu May 16, 2002 11:37 am

The power supply seems to be the noisiest component in a PC (apart from Pulsar of course

). My current one is driving me nuts. So when choosing a quiet power supply, how low can you go?

The famous QuietPC power supplies "only" go up to 300w. I've also just found the CWT 300-12 from BlackNoise another cheaper 300 Watter. Anyone used one?

How do you calculate the power requirement? Would 300W be enough for a P4 Northbridge system with Pulsar II, Matrox 550, maximum 3 harddisks, CD-RW/DVD, floppy, etc.?

Answers on a postcard please to doodyrh c/o PlanetZ, cyberspace

[ This Message was edited by: doodyrh on 2002-05-16 12:40 ]

remixme · Post by **remixme** » Thu May 16, 2002 11:50 am

Thats a tough question mainly becuase two power supplies both rated at the same wattage may not power the same amount of devices.
Also bear in mind that if they do have enough juice to power all that stuff.
Remember that they are thermally controlled.
A sound measurement of 26.4db is at nominal load, ie 1 hard drive, 1 cd-rom moderate cpu and mb.
The noise may well be a lot higher if you add more components.

I hope to be sourcing a new manufacturer of quiet power supplies for our video edit machines. I'll let everyone know the results when I get them.

doodyrh · Post by **doodyrh** » Thu May 16, 2002 1:04 pm

On 2002-05-16 12:50, remixme wrote:
Remember that they are thermally controlled.
A sound measurement of 26.4db is at nominal load, ie 1 hard drive, 1 cd-rom moderate cpu and mb.
The noise may well be a lot higher if you add more components.

Good point, remixme

subhuman · Post by **subhuman** » Thu May 16, 2002 1:27 pm

Antec and Enermax both make great supplies, and have Fan Control versions (some non-FC/FCA versions of Enermax are loud, beware)

The PC Power & Cooling ( http://www.pcpowerandcooling.com ) have a quiet, very high quality supply in much higher wattages. Take a look.

remixme · Post by **remixme** » Thu May 16, 2002 1:35 pm

Did you see the price of their ultra-silent 400w psu! Ouch! Thanks for the link though.
I should imagine its pretty tough to get a psu that has a large output but does not sound like a ten ton truck, or perhaps they have the market cornered. I haven't seen any 400w quiet psu, (possibly enermax) although I haven't particularly looked.

doodyrh · Post by **doodyrh** » Fri May 17, 2002 1:26 am

Thanks Guys. I'm still wondering if 400W is really necessary though.
It seems like calculating your power requirement is not an exact science.

On 2002-05-16 14:35, remixme wrote:
Did you see the price of their ultra-silent 400w psu! Ouch!

Precisely. That's why I'm wondering whether 300W will do. Their 300W 'topseller' is much cheaper.

I followed the order process through to the last page at quietPC. The unit is advertised at 54 GBP. With VAT and delivery to Germany it was over 101 GBP! Also Ouch!

I sent them a polite mail explaining why I didn't order. They kindly gave me this website which I don't think is related (?)

at0m · Post by **at0m** » Fri May 17, 2002 6:45 am

Any one bought affordable silent fans/power supplies in Belgium? I found a shop in the UK, but UK's expensive... so why wouldn't I get it 'round the corner?

Neutron · Post by **Neutron** » Fri May 17, 2002 6:59 am

I just buy an enermax power supply (which they call "whisper" but are not that quiet), Then take out the fans, leave the second one out, and replace the rear one with a panaflo or silencer fan. never had any trouble with that and its not much more expensive than a regular chinese power supply.

I used the enermax 430 watt one on one machine but I think it is overkill for a p4, the 350 should be enough. 430 if you have an AMD with lots of hard drives and stuff.

you can even do this. get a fan with a 3 pin connector on it. feed the wire out of the power supply and use the "power fan" header on the motherboard. then you can monitor that fan like you can with the PSU fan.

also that way you dont need to cut any wires
and can put the old fan back if you like.

[ This Message was edited by: Neutron on 2002-05-17 08:17 ]

remixme · Post by **remixme** » Sun May 19, 2002 1:31 am

Great tip neutron I will be trying this,
just one thing, about fan monitoring, the fan doesn't need to be drawing power off the motherboard to be monitored does it?

Can you just connect the one monitor wire to the middle pin on the mb fan header?

I'm also assuming this voids the warranty on the enermax supply?

orbita · Post by **orbita** » Wed May 22, 2002 8:05 am

Hi
I use 300 watt Q power supplies in my 2 main machines.
One machine has 2 dsp cards, 2 harddisks, PIV 2Ghz, matrox card etc. That runs lovely.

The other machine has 3 harddisks (2 scsi) XP1700, matrox card. That also runs fine.

I use the 250watt Q power supply in my celery300 machine which is just for playing mp3s and internet downloading. I leave that on 24 hours a day and its virtually silent. The 300watt ones make almost no sound too.

I have a 4th machine that acts as a fileserver that has 5 disks running 24/7 and that is happily using a 300watt supply.

You only really need higher than 300watts if you plan on using using serious quantities of harddisks and stacked with powerful pci cards.

The Q power supplies are a little more expensive than most but they have been highlighted recently in a magazine as a good way of reduction audio & electrical noise in your pc.

[ This Message was edited by: orbita on 2002-05-22 09:08 ]

Neutron · Post by **Neutron** » Sun May 26, 2002 8:40 pm

You could monitor only from the motherboard, but a fan uses so little power compared to everything else (cards and cpus and ram etc) i would not worry about it.

You would void the warranty on your PSU just by opening it. Its just a PSU though

Im pretty sure its not the middle pin BTW i would have to check to be sure.

at0m · Post by **at0m** » Tue Jun 11, 2002 9:41 pm

I've installed http://www.pabst.de silent fans on my CPU's and in PSU, as per Neutron's mod. It works just great, my pc's become soooo silent!!!!

doodyrh · Post by **doodyrh** » Sun Jun 23, 2002 4:25 am

I plumped for the BlackNoise 300W in the end, partly because it was stocked by the supplier of most of the other stuff I needed. It's pretty quiet except for the inevitable sound of air flow. 300W seems to be adequate.

I ran it for a short time without the CPU fan and it was bliss. So I also put in a Pabst which is better but by no means silent.

orbita · Post by **orbita** » Mon Jun 24, 2002 4:41 am

there are different power pabst fans, the quiestest ones run at 12db which is pretty much silent!