PSUs - safezone for PSU currents? (esp. Silent PSUs)

MIDIman

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Jan 14, 2000
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Hi all - I've heard alot about a rail being a certain percentage over or under, my motherboard monitor has such ratings/settings, and I'm seeing such terms more and more in PSU reviews etc.

So, out of curiosity, what is the safe operating area for a PSU. i.e., when I read a review concerning this on a PSU and I'm comparing it to anther's currents, what should I look for?


Specifically, I'm picking out another PSU to silence my system. See the chart at the bottom of this link I trust this site because they have a very solid way of testing noise levels in anechoic rooms. I currently have a super quiet zalman, and I'm looking for even better, but I just didn't know how to compare these beyong looking at noise levels!
 

DAPUNISHER

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The only PSU besides Zalman that I'm familiar with that is super quite and can recommend looking into is seasonic
 

myocardia

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Jun 21, 2003
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Here's another vote for the Zalman. I've read quite a few reviews of them, and not only are they quiet, they have very stable rails. That is what you're looking for for in a psu, isn't it? If not, I have some old psu's that I can take the fans out of!:D Anyway, the best you can do with a psu is as close as possible to 12.0v, 5.0v, and 3.3v on those 3 rails. Most people consider an absolute maximum of +/- 10% to be the deciding factor of when a psu has "gone south", although some of us like ours to be much closer to spec. And since you weren't very clear in what you were asking, if you meant "how much power do I need in each rail", that's going to depend completely upon what components you're running, and nothing else.
 

Shimmishim

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Feb 19, 2001
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+/- 10% is key.

Good psu's are within +/- 5%

really good ones are +/- 3%

and the absolute best ones are +/- 1%


I run mine at 3.6, 5.2, 12.8

:)

good stuff!
 

Soulkeeper

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Nov 23, 2001
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i've always noticed that antec, enermax, and a few of the top name psu's don't supply enough voltage and often fall below on all rails except maybe the 12v rail which is often over powered

get a psu with voltage control and fan speed control and you'll be set
if you can't get one with fan speed control you can always change the fan by yourself
also i recommend accepting 400watts as you absolute minimum for any system today even over 450 if you can aint too high

good luck
 

Shimmishim

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Feb 19, 2001
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well...

it's true that things do fall under load...

but the ones with pots that you can adjust such as the 550 w antec... aren't all that great...

i think the best thing to do is to physically mod the psu yourself to get stable voltages...

:)

like me!!! woo hoo!!!
 

wicktron

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Aug 15, 2002
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Originally posted by: Shimmishim
well...

it's true that things do fall under load...

but the ones with pots that you can adjust such as the 550 w antec... aren't all that great...

i think the best thing to do is to physically mod the psu yourself to get stable voltages...

:)

like me!!! woo hoo!!!

Hah. I got 12.2/5.2 out of the box with TTGI 550w.
 

fusionpit

Senior member
Jul 29, 2003
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Originally posted by: Shimmishim
+/- 10% is key.

Good psu's are within +/- 5%

really good ones are +/- 3%

and the absolute best ones are +/- 1%


I run mine at 3.6, 5.2, 12.8

:)

good stuff!


Strange, My Generic PSU does 3.23, 5.05, 11.8, -11.85 and -5.04
 

Shimmishim

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Feb 19, 2001
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the question is though, how stable are they?

it doenst matter what the rails are at idle... the qutestion is what are they under load and how much do they fluctuate.
 

MIDIman

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+/- 10% is key.
Good psu's are within +/- 5%
really good ones are +/- 3%
and the absolute best ones are +/- 1%

Thats what I was looking for - thanks!

Has anyone used the

Fortron FSP300-60PN or the Fortron Aurora FSP350-60PN? Both are generally quite a bit cheaper than the other quiet PSUs, but still keeping around ~20db. After the anandtech review, I wasn't able to conclude if these were actually good buys or not. The Aurora seems to be a nice upgrade as it adds a knob for speed control (I could care less about the fancy leds).

Thx for the replies.
 

Shimmishim

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Feb 19, 2001
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Originally posted by: MIDIman
+/- 10% is key.
Good psu's are within +/- 5%
really good ones are +/- 3%
and the absolute best ones are +/- 1%

Thats what I was looking for - thanks!

Has anyone used the

Fortron FSP300-60PN or the Fortron Aurora FSP350-60PN? Both are generally quite a bit cheaper than the other quiet PSUs, but still keeping around ~20db. After the anandtech review, I wasn't able to conclude if these were actually good buys or not. The Aurora seems to be a nice upgrade as it adds a knob for speed control (I could care less about the fancy leds).

Thx for the replies.


the fortron fspXXX are supposed to be awesome psu's

a long time ago someone posted a thread on how this psu only fluctuated 1% underload.

i bought this psu to try out but i couldn't get it to post on my ic7.

just be wary of how your board handles volts.

the ic7 always read voltages lower than the actual

the p4p800 i have now reads voltages higher than normal so it worked fine.

just a heads up.
 

MIDIman

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Jan 14, 2000
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the ic7 always read voltages lower than the actual
the p4p800 i have now reads voltages higher than normal so it worked fine.
just a heads up.

Thx - I have a similar problem with my Abit BD7-II...everything it reads is way too high with an Antec Tru330.

 

Soulkeeper

Diamond Member
Nov 23, 2001
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my true control 550 was a little less than i had hoped for, but with all the pots adjusted to their max i get
3.33, 5.06, and 12.29 with my overclock at around 2.7ghz
 

kursplat

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May 2, 2000
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the ic7 always read voltages lower than the actual
exactly . how do you know WHAT the true readings are . the only acurate way to check voltage is with a digital volt meter reading right off the harness.
 

Shimmishim

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Feb 19, 2001
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Originally posted by: kursplat
the ic7 always read voltages lower than the actual
exactly . how do you know WHAT the true readings are . the only acurate way to check voltage is with a digital volt meter reading right off the harness.

because i've actually measured it directly from my psu with a multimeter!!!

you can jumpstasrt the psu and then measure it.

:)
 

Soulkeeper

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Nov 23, 2001
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yeah i measured directly from my psu and directly off the board and all my voltage readings in the bios and in winbond hardware monitor seem to be pretty accurate for my ic7 max3

 

kursplat

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May 2, 2000
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because i've actually measured it directly from my psu with a multimeter!!! you can jumpstasrt the psu and then measure it.
good deal. but i would mesure it with everything running. during heavy fragging or running prim95 or something.
if your mb's readout are accurate thats great , but (imho) you can't be sure untill you test it.
 

computerpro3

Senior member
Dec 19, 2003
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my ic7 readings are WAY off...

i was looking into a pcpowerandcooling 510w deluxe cause my rails were real low, then i decided to measure with a multimeter for kicks while running 2 instances of prime95 and 3dmark 03 looping at once and guess what.

ic7 readings
12v= 11.56
5v = 4.7
3.3v = 3.08

multimeter readings (taken through spare molex while system was under full load)
12v = 11.98
5v = 5.05
3.3v = 3.31

ha...i uninstalled the hardware monitor shortly after. I ended up installing mbm5 to get temps, but don't trust the volts at ALL.
 

MIDIman

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Jan 14, 2000
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Anyone else have any experience with the Fortron PSUs as mentioned in my previous post?

Reason I'm leaning towards these instead of the others is they appear to have relatively the same db ratings with other quiet PSUs, but at a significant reduction in cost. The Zalman starts at $60, the Seasonic starts at $58, and yet the Fortron 300w I can get for as low as $32 - nearly half the cost!

I already have a Zalman, and love it, but honestly, I'm thinking of giving the Fortron a try. I suppose my only worry is that its going on an Abit BD7-II that appears to read volts lower than normal, and temps higher than normal...perhaps a motherboard replacement is in order as well...