Real Cost of a PSU, 80 Plus Bronze vs Gold

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zooom18

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Feb 6, 2012
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Hi All,

Wondering what the actual cost of a PSU is after factoring the 80 plus rating. My thought is this:
Build: 2500k, 560ti, 3-4 HDD

I'm looking at the Corsair 850w gold $190 http://www.newegg.com/Product/Product.aspx?Item=N82E16817139015
And the Corsair 850w bronze $135 http://www.newegg.com/Product/Product.aspx?Item=N82E16817139022

difference of $55

Calculations:

A 80 Plus Bronze between 82-85%, and a Gold between 87-90%. So a 5% difference in a 850w PSU is 42.5w of used or unused energy.

Using this tool to calculate costs:
http://www.handymath.com/cgi-bin/electric.cgi

And I will probably run my computer between 4 and 8 hours a day every day (hr * 365). Used 10 cents / kw-hr and 15c/kw-hr for a range if the cost fluctuates.
10c 4hr $6.21 a year
10c 8hr $12.41
15c 4hr $9.31
15c 8hr $18.62

(If I left my computer on all day)
10c 24hr $37.23
15c 24hr $55.84

CONCLUSION:
Assuming I use the power supply at this rate for 5 years, unless I'm running it at least 8 hours a day or the energy cost increases there is very little difference in a financial point of view. However, the Gold probably has higher quality build, 2 yr extra warranty, "eco-friendlier", etc.

Any thoughts on this? How realistic is it, did I leave anything out?
 
You seem to be assuming max load 24 hours a day. That's probably a fairly bad assumption. The real savings are most likely far lower.

That said, I just picked up an AX750 for $149. :) For me, the higher quality, longer warranty, and less excess heat were worth it...but opinions vary.
 
realistically the different is even smaller. the 5% difference of 42.5W is way too high. unless whenever your PC is on, you're loading up the full 850W (which you won't), there's only a few watts difference in terms of the efficiency difference.
 
Your computer will never, ever pull 850 watts from the wall. The most it will probably pull is 500-600 watts, and that is with a synthetic load. The most demanding games will probably make you pull 300-400 watts from the wall. Idle is another story, you're probably pulling 200 watts or less.

Unless you're planning on putting another 560 in SLI, all you need is a good 500-600 watt power supply, which will save you lots of money from an 850 watt. Good ones run in the $50-80 range.
 
Paul_Johnson said:
Ignore the other pages in this article since the content manager has mangled them, but I ran some of these numbers a while ago for an article: http://www.hardocp.com/article/2011/09/15/80_plus_irrelevant_to_you_when_buying_psu/2
Click to expand...

Yeah thanks Paul, I actually saw that after I posted this. So since the rating is pretty irrelevant what should be a good indicator on which psu to get?

From Tsumi's post it looks like I could get by with a 650w, any good recommendations, and why?

Thanks
 
You can get the Seasonic S12II 620 watt for just under $60 on Newegg after promo code.

The Corsair CX600 V2 is $40 after rebates and promo code, also on Newegg. Not as good quality as the S12II though.
 
zooom18 said:
Yeah thanks Paul, I actually saw that after I posted this. So since the rating is pretty irrelevant what should be a good indicator on which psu to get?
Click to expand...

Quality, performance and reputation. For example, the "80-Plus Bronze" category includes both good- and crappy-quality PSUs. However, the lack of an "80-Plus" certification or a manufacturer-claimed efficiency rating of less than 80 percent these days almost certainly guarantees an old-design and/or low-quality PSU that's unsuitable for powering anything current.
 
Tsumi said:
Your computer will never, ever pull 850 watts from the wall. The most it will probably pull is 500-600 watts, and that is with a synthetic load. The most demanding games will probably make you pull 300-400 watts from the wall. Idle is another story, you're probably pulling 200 watts or less.

Unless you're planning on putting another 560 in SLI, all you need is a good 500-600 watt power supply, which will save you lots of money from an 850 watt. Good ones run in the $50-80 range.
Click to expand...

Agreed that it will never pull 850 watts, I would be very surprised to see it pull 375W load and idle at anything over 115W, unless he gets crazy with voltage...
 
This is like one of those attempts to compare the cost of a hybrid to the cost of a regular car and figuring out if you can make up the price difference in what you save in gas

It doesnt really work so well.

Name brand and price point will be your best bets Without SLI or any funny stuff you shouldnt need an 850W psu anyways, so with either of those buys you will waste money on excess wattage
 
TehQuick said:
If the OP goes SLI route, the computer will start pulling 850 or even more watts from the wall ;)
Click to expand...

With two 560s? I highly doubt it, unless he gets a relatively inefficient power supply. Max is probably somewhere around 700 or less.
 
But do you want to run a power supply at max for long periods of time. Less chance of failure running load in middle of high efficiency curve..
 
rascal65 said:
But do you want to run a power supply at max for long periods of time. Less chance of failure running load in middle of high efficiency curve..
Click to expand...

The problem with this argument is, are you running your computer at full capacity all the time? For at least 90% of users, the computer sits at idle most of the time. During gaming, you'll load it somewhere between 50% and 80% in terms of max power pull, depending on game and setup.
 
Well I am one of the 10%, but I also want my PS to last more than 3 to 5 years.
 
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