Debunking Power Supply Myths
by Christoph Katzer on September 22, 2008 3:00 AM EST- Posted in
- Cases/Cooling/PSUs
What about Noise?
Efficiency isn't the only aspect of power supply performance to consider. Noise levels are also important. Sticking with our previous example of the Cooler Master UCP 900W, we get the following chart:
All three of our test systems allow this power supply to remain virtually silent. Even with our high-end system, power supply noise should not be much of a concern. In order to achieve a power draw of 550W, you will need to have a lot of power-hungry components, and these will almost certainly drown out any noise created by this particular power supply. Naturally, this is one of the benefits of choosing a power supply rated much higher than what you actually need: it will always stay virtually silent.
Any of our three sample systems will allow this power supply to run at less than 20 dB(A). Not surprisingly, this is the sort of comment we see on forums. "I have PSU XYZ, and I never hear it when my system is running!" That might be true, but without knowing the system components and operating load, such a statement provides the very little useful information -- especially when discussing an 800W or larger PSU. We prefer to push power supplies to their limits to see what actually happens when you begin to tax them. Midrange and high-end systems almost always have plenty of other fans that will drown out such a power supply.
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Dancer - Thursday, October 22, 2009 - link
On the face of it, this article seems an excellent, well-researched contribution to a highly vexed question. I do have a concern, however: We know that the power output of a PSU drops as it ages. We also know that this drop depends partly on quality and partly due to random chance. If I'm buying a PSU to last 3, 5 or more years, will this seriously affect the capacity of the PSU I should buy for a given machine?internetrush - Saturday, June 6, 2009 - link
Ok, lets low ball it, im running 200w (average) per graphics card, about 50w cpu (core i7) and three hard drives.Lets see
200 x 2
+50 + 50 (motherboard chipset)
+30 Sound card
+10 cd drive
+20 (fans)
During a game, much less a stress test, im lowballing a 600w load on my PSU.
If i had an 800w PSU that would be 80% of its total output, which thereby increases its heat and decreases its life.
When you buy a 1000w PSU, not only are you ensuring that you will never watch your computer go up in smoke (had a friend do that to a 350w on an old P4) but you are also not having to replace it whenever you buy a new processor or add something to your system.
This article is good, however, on a tech website i would expect a bit more consideration for the higher end gamers and common sense.
Common sense says, if you are a higher end system user, you WILL expand said system!
For gods sake! Some cards today use up to 500w power (the 4890X2 and new 295 SuperCard).
As a gamer, id rather have a 2000W PSU that id never have to replace than a 400w that would FRY as soon as i threw on a new video card.
Christoph Katzer - Saturday, August 8, 2009 - link
Sorry for the late reply.You are probably right when you see it from the perspective of a high-end-hardcore-gamer... But do you know how small the percentage of people is who actually own a real high-end system?
JohnMD1022 - Sunday, March 15, 2009 - link
It would be nice if you could periodically update this with newer components.lopri - Tuesday, April 28, 2009 - link
BillyBuerger - Sunday, October 26, 2008 - link
Anyone have any info on that Thermaltake QFan 300? That thing looks great efficiency wise. Not normally a Thermaltake fan. And the fan controller looks like it sucks. Just keep it below 150W... Or fan swap.Christoph Katzer - Thursday, October 30, 2008 - link
I will have a review up soon!Cincybeck - Tuesday, September 30, 2008 - link
Couple of "knowitall" friends were trying to tell me I was going to need a larger power supply when I built my new system. Which in turned incited the Microcenter sales person saying oh yea you're probably going to need that too. I turned around said I estimated these parts to draw at most around 200, 250 watts, and I have a 500W Seasonic M12. Shut him up pretty quickly, but my friends were still pushing it the whole way home. So now if they ever bring it up again I can print this article and shove it in their face. Thanks =D0roo0roo - Sunday, September 28, 2008 - link
i like the graphs:)keep it up!
this is the info we need!
normally the psu market is just lousy because of the lack of any real information.
mark84 - Friday, September 26, 2008 - link
For those quoting that old link for the AtomicMPC graphics card power thread, the new/current one is being maintained here http://forums.atomicmpc.com.au/index.php?showtopic...">http://forums.atomicmpc.com.au/index.php?showtopic...