Power Supply Efficiency - 80 PLUS

Alot of talk about power supplies lately with recommendations to get 80 Plus Silver or better. Some people may not understand what this means so i made a crappy table to help :) Note that these specs do not apply to server power supplies.

% of Load:	10%	20%	50%	100%
80 Plus	n/a	80%	80%	80%
80 Plus Bronze	n/a	82%	85%	82%
80 Plus Silver	n/a	85%	88%	85%
80 Plus Gold	n/a	87%	90%	87%
80 Plus Platinum	n/a	90%	92%	89%
80 Plus Titanium	90%	92%	94%	90%

This table shows the minimum efficiency required to get 80 Plus certification. For each test at 20%, 50% and 100% load, the power supply must meet the minimum requirements for ALL 3 (ALL 4 in the case of Titanium) in order to be certified.

Why does it matter?

Let's say you have a 300W power supply that's only 60% efficient, such as one you might find in a computer you got from Best Buy. If you run it at 100% load, you'll get your 300W, but you'll draw 500W to do it, shooting your electric bill sky high. You might ask what happened to the other 200W? It's all converted to heat, which will make your air conditioning run more often, shooting up your electric bill even more, not to mention making it much tougher to keep your computer cool.

So you get fed up with the garbage power supply and get a basic 80 Plus 300W one. Running it at 100% load, you get your 300W, but only draw 375W to do it, producing only 75W of heat. Your wallet, computer and air conditioning unit thank you.

Let's say you get frustrated with the 80 Plus and decide to go all out on an 80 Plus Platinum. Running it at 100% load, you get your 300W, but only draw 337W to do it, producing only 37W of heat. Your wallet, computer and air conditioning unit throw you a party.

In this example, going from a garbage power supply wasting 200W in heat, to an 80 Plus Platinum wasting only 37W, you save 163W/h. That equates to 117.36 kW/h off your electric bill each month, or about $14.08 off your bill at the national average of $0.12 per kW/h = $169/year.

The savings are even more on larger power supplies, as only a 300W was used in this example. The savings are greater still when you get a power supply that can provide more wattage than you need, meaning it runs at a 60% load which is more efficient than maxing it out (45%-70% load is best).

Thanks for this! I always confuse myself when it comes time to buy a PSU, since I do it so infrequently.

Can this be made a sticky?

It's now stuck!

Thank you JPM, this is a great post.

I always use this little handy tool:

http://www.extreme.outervision.com/p...ulatorlite.jsp


I will give a pretty good estimate on how big a PSU is needed. Use it in combination with the first post.

Quote:

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Originally Posted by Beerdrinker

I always use this little handy tool:

http://www.extreme.outervision.com/p...ulatorlite.jsp


I will give a pretty good estimate on how big a PSU is needed. Use it in combination with the first post.

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That's a great tool. Thanks for the link.

In your eyes whats better ? I need a power supply for my 8 core Xeon with 2 Ati cards 7970 and 7950 and three little Nvidias 660,640,750ti
Thinking about

be quiet! Dark Power Pro 10 1200W ATX 2.31 (P10-1200W/BN205) or
LEPA G 1600W ATX 2.3 (G1600-MA)

Both cost about 400$ ,therefore price dont matters.

Hi Conf,
Johnny Guru has a nice test on the LEPA G 1600W here. Looks like he really liked that PSU. Couldn't find a review in English to read on the Dark Power Pro 10 1200W.

They are obviously nice PSUs, but $400? :confused: That is a serious chunk of change for a PSU! Is there anything somewhat less cost that you like, or are you just going for massive high end?

I know they are running 24/7 so I always try to take the best of the proper Watt class.
They should run for years without any problems so I have some of them.
Mainboard and PSU and the case is nothing to look after your money.
In summer they have to run with 38 degrees Celsius and the best ones do this.

Bump

Updated table - added Titanium

Yeah, if you have 3 computers in a small home office (like me), you'll definitely notice a heat difference. Also, my budget billing electric payments have been going down every month since swapping my last generic PSU for a Gold.

Quote:

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Originally Posted by trigggl

Yeah, if you have 3 computers in a small home office (like me), you'll definitely notice a heat difference. Also, my budget billing electric payments have been going down every month since swapping my last generic PSU for a Gold.

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Take it from someone paying SoCal electric rates...you WILL notice a difference on 24/7 crunchers. :cool:

Well, EVGA's new Titanium PSU is probably what i'm going to buy from now on. Price? Who cares. As i demonstrated in the first post, these things pay for themselves no problem. Overkill on the wattage? Who cares. It's still really efficient. Not having to replace a PSU for 10 years? Yes, please.

http://www.evga.com/Products/Product...220-T2-1600-X1

Can be found a bit cheaper on Amazon.