Agonizing over PSU

PSUs: The source of DC power for all components in the PC & often a big noise source.

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Asai
Posts: 5
Joined: Thu Jul 19, 2007 3:48 am

Agonizing over PSU

Post by Asai » Thu Jul 19, 2007 6:10 am

Hi all!

A few weeks ago one of the fans on my Chieftec PSU started screeching and I had to take it out and temporarily replace it for a thicker fan attached on the outside.
My first thought was to simply replace the fan but I discovered it's not easy to find a replacement of the same size, wich is the only one that fits. Then I thought that, since my ears are kind of sensitive and they sometimes actually hurt after a day near the PC, I might as well switch the PSU itself - after all, I already replaced the CPU sink and the VGA fan for more silent (and, I think, efficient) devices.

My doubts began when I came across the PSU catalogs online. My mobo requires a 350+w(!) PSU with a 12v-18A rail.

Problem:
Very few PSU have 12v-18A below 600w versions! :shock:
Those that have it are mostly PCF passive, low efficiency, and rarely low noise. Most have no info at all regarding protection systems and Rohs certificates.

What would be more enviromentaly friendly?

- Something like a Corsair, even though it will never actually use 520w?
- A lower wattage PSU with a lower efficiency? like BeQuiet Dark Power P6 Pro 430W (not much difference in efficiency, but more noisy, some reported trouble and unknown protections *sigh*)
- OR should I just order new fans from some faraway place and keep my Chieftec running? It think it does have passive PCF, wich is a pro, the con being the fact that it runs a bit hot no matter how cool the weather is. And around here the weather is not cool at all most of the year... I don't remember the last time I had my case closed and I still think the CPU should be a little cooler....

By the way, I was thinking replacing the fans (currently Adda) with Silenx. But I don't know if they should have the same amps (0.12 and 0.15) or if that makes no difference at all as long as I get the volts right. I totally suck at sciences... :oops:

PS - I'm not overclocking.

jaganath
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Location: UK

Post by jaganath » Thu Jul 19, 2007 8:59 am

My mobo requires a 350+w(!) PSU with a 12v-18A rail.
if specs are the same as in your sig, you only need 180W max.Seasonic S12-330/80.

Asai
Posts: 5
Joined: Thu Jul 19, 2007 3:48 am

Post by Asai » Thu Jul 19, 2007 2:20 pm

Hi! Thanks for replying. :)

Those values are specifically mentioned in the mobo's manual, the watts as highly recommended and the amps as "should be greater than". The Chieftec PSU covers both, so I started from there.
The system is what is in my sig plus an ocasional extra HD, a multi-card reader, and the floppy drive. Not much of a burden.

I had considered those Seasonic as well (checked the whole s12 series, in fact) and, while I've been getting different answers on what my system should truly need in wattage and why (ranging from values like your 180w up to 330w or so), I don't know if using a lower amp might cause the board not to work so well... I can fix plugs and build lamps, but that pretty much sums up my knowlege of electricity. :P
The Seasonic S12 only gets a 12v-18A rail on the 600w version and that same happens with most brands.

dhanson865
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Location: TN, USA

Post by dhanson865 » Thu Jul 19, 2007 2:56 pm

Please read this:
Confused about Dual 12V lines? Here's the FAQ!
viewtopic.php?t=23916

In short you don't have to have 18v on a single line on the PSU specs because for example a PSU might say it has 17 + 17 and in reality its just 34 volts on a single "rail" or pool if you prefer that term.

Also look at http://www.silentpcreview.com/article28-page4.html for some real systems monitored for power usage.

for example:

Intel Pentium D950, overclocked / overvolted 10% (Presler, 3.74GHz)
Asus P5LD2-VM motherboard
4 x 1024MB Corsair DDR2-6400 RAM
ATI Radeon X1950XTX-512 PCIe graphics
Hitachi Deskstar 7K80 80GB hard drive
WD Raptor WD1500ADFD 150GB 10krpm HDD
1 x 120mm fan

all that takes less than 300 watts at full load.

Asai
Posts: 5
Joined: Thu Jul 19, 2007 3:48 am

Post by Asai » Fri Jul 20, 2007 2:48 pm

Oops! Moved. Yeah, I guess my "green PSU" did end up being more PSU than green... Sorry. :oops:

dhanson865 - Doh! That rail thread was one of the very first things I read and I tottaly forgot about it! This kind of stuff just doesn't stick to my memory... :roll:
That does leaves me a lot more room to manouver.
Thanks for explaining! :)

dhanson865
Posts: 2198
Joined: Thu Feb 10, 2005 11:20 am
Location: TN, USA

Post by dhanson865 » Sat Jul 21, 2007 12:01 pm

Here is a thread where we bandied about the options for cheap to medium priced PSUs

viewtopic.php?t=34943

Asai
Posts: 5
Joined: Thu Jul 19, 2007 3:48 am

Post by Asai » Sat Jul 21, 2007 3:34 pm

Thanks!

I'm seriously tempted by the s12-380w, as jaganath suggested. There's still a store that sells them around here. They may not be the cheapest, but at least I'll know what I'm buying. The most popular brands being sold here come with very little info. I really hate that!
I just hope if I ever have to change my VGA this one will still do. Still, I figure I can always put it on my brother's PC... ;)

Asai
Posts: 5
Joined: Thu Jul 19, 2007 3:48 am

Update :)

Post by Asai » Wed Jul 25, 2007 2:52 pm

Well, I just finished installing my new PSU - I went for the s12-380w - and everything seems OK. I just wish the cables came out on the other side, but one can't have everything.
The system is now so quiet I've just realised for the first time in years that my Seagate makes a little noise! :P It's not loud at all but it's high pitched and this kind of sound tends to get to my nerves, so... Next stop - dampening the HD.

Thanks again for your help, guys. :)

Wibla
Friend of SPCR
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Location: Norway

Post by Wibla » Thu Aug 02, 2007 6:25 am

I know what you mean.. after I moved my pc to a nearly silent room I noticed what actually made noise.. and it was the seagate drives, too bad I have 3 of them :(

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