80 PLUS Efficiency and What It Really Means

[Mail me to the Moon]

19 minutes ago, seon123 said:

Please don't quote the entire post

There we go, my bad

[EsaT]

I think this article about amount of power lost would be good addition to starting post:

http://www.silentpcreview.com/A_Better_Way_to_Compare_PSU_Efficiency

[MithicSpirit]

On 8/4/2015 at 2:04 PM, Aytex said:

It is impossibru to achieve 100% efficiency

Unless you have a superconductor

Wikipedia article

[Stefan Payne]

4 hours ago, MithicSpirit said:

Unless you have a superconductor

Wikipedia article

Not even then as you have to take the power consumption of the controllers into account, the MOSFETs and the Magnetics.

 

We are already at the upper end, halving the Power Consumption might be possible but it will be very expensive.

[tonymc]

On 8/4/2015 at 2:03 PM, STRMfrmXMN said:

All the time I'll see people recommend PSUs based on efficiency. This, although fundamentally a good idea so that you don't end up with a stick and some chewing gum powering your system
 

To begin with, his conclusions are very accurate.

Do you have PSU recommendations by brand and models at least one year ago to date? Or have examples of PSUs that are less recommended than the competition even if they have more publicity or are more "nice".
Almost always a product with more publicity, is not synonymous with quality, but the amount of money that the company invested in advertising. Where are the reliable references to choose a good PSU among so many offers?

[OrionFOTL]

4 hours ago, tonymc said:

Where are the reliable references to choose a good PSU among so many offers?

Your references for choosing a good PSU should come from professional tests and reviews. Currently the best PSU reviews can be found at TechPowerUP, Tom's Hardware and KitGuru. Watching for some real-life issues is important too, like in the case of Seasonic Focus Plus.

[tonymc]

3 hours ago, OrionFOTL said:

Your references for choosing a good PSU should come from professional tests and reviews. Currently the best PSU reviews can be found at TechPowerUP, Tom's Hardware and KitGuru. Watching for some real-life issues is important too, like in the case of Seasonic Focus Plus.

Thank you
Problems with Seasonic Focus Plus! Very interesting, I will look for information about this.

[Guest]

tldr; means literally nothing

 

post should've been just this sentence and nothing else, 80 plus ratings are a terrible indicator of build quality (case in point: 80+ gold rated rosewill PSUs)

[Constantin]

On 8/4/2015 at 9:03 PM, STRMfrmXMN said:

All the time I'll see people recommend PSUs based on efficiency. This, although fundamentally a good idea so that you don't end up with a stick and some chewing gum powering your system, shows that most do not understand what 80 PLUS efficiency implies. Let's get a couple myths out of the way:

- "A higher 80 PLUS rating correlates to better quality." Incorrect. Certain components in a PSU do need to be of a certain quality to achieve higher efficiency, however, quality of soldering, capacitors, etc, can be forgone in achieving an exemplary 80 PLUS rating. Electrical performance can be ditched as well. I like to use the EVGA G1 as an example of this. It's made of above average componentry, performs lackingly, and achieves gold efficiency. Then there's the EVGA B2, which is constructed about as well, performs better electrically, and advertises 80 PLUS Bronze efficiency (it actually achieves 80 PLUS Silver efficiency but that standard has been given up by and large). The EVGA B2 is a better PSU than the G1, yet it wastes slightly more electricity. This will correlate to a marginally more expensive power bill (pennies on the dollar for most home users) but ensures you a better power supply for your money. If, however, you plan to run a very power-hungry system for several hours on end then a more efficient power supply can save a more noticeable amount of money, especially if used heavily during hours of the day where electricity is more expensive.

 

On another note: some brands will undersell their unit's rated wattage if it can achieve higher efficiency at lower loads, I.E. a brand may sell a 550W 80 PLUS Platinum rated unit that can actually output 600W+ but would have to be advertised at a lower efficiency rating if they were to sell it at that rated wattage.

- "Higher 80 PLUS efficiency keeps the PSU cooler." Not to any serious degree, but this is technically true. A less efficient PSU will waste more electricity and wasted electricity is turned into heat. This is not likely to have an appreciable impact on the temperature of your room or system however as your system doesn't really draw that much power, thus it's better to optimize your system's airflow before throwing an AX1500i in your system to minimize heat created by the power supply. Since PSUs exhaust heat anyways the temperature of your system's hardware will not be impacted to any noticeable degree. Different PSUs also handle cooling differently and 80 PLUS efficiency doesn't correlate to the size of the fan used or the heat-dissipation abilities of the unit.

 

- "Power supplies are most efficient at around 50% load." This is, by and large, untrue, and seems to be set in stone by many simply because the peak efficiency measured by Ecova's testing of just three load levels is at 50% always. Many manufacturers or reviewers test PSU efficiency at different loads and post charts online, if this matters to you, but many PSUs are more efficient at 60% load than 50% and many are more efficient towards 30%. Don't buy a PSU based on how efficient it will be with whatever hardware you have in it. Different topologies and different PSU platforms handle efficiency differently. This should be a non-issue and you should be looking at buying the best PSU you can get with your money.

 

- "If you have a 1000W PSU with an 80% efficiency then you are only going to be able to get 800W from your power supply." This is incorrect. If you have an 80% efficient 1000W PSU then, when putting it under enough load to max its output you are going to be drawing more power from the walls - not losing output from your power supply. In this instance, putting a 1000W PSU under max load with an 80% efficiency would mean you're drawing 1250 watts from the wall. Math goes as such:
                                                                                                X / Y= Z                  
                                                                                        1000W / .80 = 1250

                                                                                  1250W drawn from the wall

X represents the wattage you're using (say 350W with a Ryzen 5 1500X and GTX 1080 Ti under 100% system load), Y represents the efficiency in decimals (an 85% efficient PSU would be .85), and Z represents your total system draw from the wall. For this calculation we're assuming that the PSU in question has exactly enough wattage to power the system at 100% load and is 87% efficient at 100% draw, making it an 80+ Gold efficient power supply.


So in our case with the 1500X and 1080 Ti:

                                                                                               350 / .87

                                                                      = 402 watts drawn from your power outlet

 

Note, however, that efficiency is not consistent throughout the load of the power supply.

Power supplies are more and less efficient at different loads. They are also more efficient when connected to a more powerful grid, the 230V nominal, which you may use if you don't live in North America. Check that your PSU allows for operation under both voltages. Most modern ones switch operation automatically. Other, often older units, will have a hard switch at the back of the unit to switch to choose from either 115V or 230V (note, DO NOT SWITCH TO THE ONE THAT DOESN'T MATCH THE ELECTRICAL OUTPUT OF YOUR WALL OUTLET! This doesn't usually end well!). This graph demonstrates the efficiency curve of a Corsair TX750 when plugged into a 115V AC versus being plugged into a 230V AC. Note the TX750 is an 80+ Bronze rated PSU.
                

                                      

 

If you live in the United States, for example, you are using a 110-120V (115 nominal) AC through a standard NEMA 5-15 socket. Your power supply may be more or less efficient than your manufacturer claims because they may advertise efficiency through a 230V AC, though standard 80 PLUS efficiency testing is done on a 115V AC. Note that these tests for efficiency are also done under very specific test environments and do not necessarily reflect real-world scenarios so you may achieve higher or lower efficiency than rated by the manufacturer.

And just to finish up let's go list the various 80 PLUS ratings and their efficiency at different power draws on a 115V and 230V AC as well as 230V AC redundant.

                                                                               

 

                                                                          

Note that Silver isn't really used anymore and the efficiency of a PSU that would achieve Silver certification would typically just be rounded up or down to Bronze or Gold. "230V internal redundant" refers to efficiency in a redundant scenario like in a data center. This guy from Dell explains it.

 

One last thing I want to make a little more hard-hitting here. 80 PLUS efficiency ratings were invented to save corporations and industrial services money in the long-term, not home users! A company with 1000 computers all consuming 100W for 10 hours a day will see a much greater benefit from having all 80 PLUS Titanium units in their systems than you likely would with your system. Don't spend tons of money trying to get a super efficient PSU when a PSU that's just as good, costs less, and achieves a tier lower 80 PLUS rating is drastically cheaper. 

 

Resources:

Ecova (formerly Ecos), the 80 PLUS certification founder (and located very near me in Portland!)

Wikipedia - There's more info here if you want to go down the Wikipedia rabbit hole

Plug Load Solutions - A list of all PSU companies and how many different PSUs they have that achieve Ecova's various 80 PLUS standards.

WOW those punctuation marks,,,,,,, "and" the grammar!

Will make my eyes hurt for a month

[seon123]

6 hours ago, Constantin said:

WOW those punctuation marks,,,,,,, "and" the grammar!

Will make my eyes hurt for a month

Please don't quote the entire post

[Mellperbia]

This is very useful, thanks

[Guest]

but but but but if efficiency ain't nothing to do with the 50% myth could it be that the 50% myth is actually refering to something else entirely??
something that is not named in this post

[Stefan Payne]

Its just ancient Knowledge that got obsolete because technology changes.

That might have been the case at some point in time or rather assumed...

But with newer technologys and different topologys for PSU, that claim just got obsolete.

 

Its the same with Caps.

Back in the day, it was true that you look for the voltage and Capacitance and that is the important.

 

Today the Capacitance and voltage is the least important measure. With Capacity you can go at least one or two numbers up or down, the Important measure is the Impedance today...

[Mark Kaine]

Can someone give me a tldr of the OP?

It's not that I'm lazy,  it's just too much data lol.

 

 

And my PSU is silver plus,  does that mean I'm a dinosaur? 

 

 

Edit:  also just use this 

https://www.bequiet.com/en/psucalculator

 

It gives you a nice range of recommendations with %, efficency and whatnot. 

 

[STRMfrmXMN]

On 11/21/2019 at 2:57 PM, Mark Kaine said:

Can someone give me a tldr of the OP?

It's not that I'm lazy,  it's just too much data lol.

 

 

And my PSU is silver plus,  does that mean I'm a dinosaur? 

 

 

Edit:  also just use this 

https://www.bequiet.com/en/psucalculator

 

It gives you a nice range of recommendations with %, efficency and whatnot. 

 

There is no TL;DR. There's too much necessary explanation for the rigmarole methodology of 80 PLUS testing. There's also many misconceptions.

 

Also, that calculator and all other calculators overestimate. Never seen one be very accurate. 

[Mark Kaine]

12 minutes ago, STRMfrmXMN said:

There is no TL;DR. There's too much necessary explanation for the rigmarole methodology of 80 PLUS testing. There's also many misconceptions.

 

Also, that calculator and all other calculators overestimate. Never seen one be very accurate. 

 

See I don't believe they "over estimate" at all,  what this calculator gives me is very very close to what everyone else tells me is mathematically the minimum and correct.  Maybe 20-30w too much but that's more of a safety margin than anything.  Which is a very right and important thing to do.

You also preferably have some leverage because thats were a PSU is actually the most *efficient*. So going for the lowest possible is something you can get away with, but less from ideal.

 

 That's just common sense (and math I guess) and also cheaper in the long run because of what *efficiency* literally means, as well as better for the environment!

 

 

The vast majority of defective PSUs is people under estimating what they need plus being poor quality, the disaster is pre programmed. 

 

 

In fact I'm always surprised how low the estimates are on that bequiet calculator... 

 

But yeah,  didn't expect such an answer... You need some safety margins,  otherwise this is just a bit negligent any kinda misinformational.  

 

 

[Subs]

In a modern pc setup, is it recommended to use AVR? From where I am our voltage is 220 and we do sometimes experience power issue. Does the new power supply once enough to protect the PC if we do direct plug to the wall?

[theo.r]

On 8/4/2015 at 2:04 PM, Aytex said:

It is impossibru to achieve 100% efficiency

I mean I guess i think that the highest you can get 94% efficiency

https://www.maketecheasier.com/80-plus-power-supply-ratings/

[Ankerson]

On 10/22/2020 at 10:06 AM, theo.r said:

I mean I guess i think that the highest you can get 94% efficiency

https://www.maketecheasier.com/80-plus-power-supply-ratings/

 

Almost 95% (94.96%) ave for the Corsair AXI 1600.

 

Peaks at almost 96%

[InfraDelta]

For an extra 40$ is it worth to get a Platinum over a Gold or is Gold good enough?
(Looking into buying a new rig with either a Seasonic Focus GX Gold 1000watts or Seasonic Focus+ Platinum 850PX, then got recommended XPG Core Reactor 750w/850w, Corsair RM750x and Corsair HX750/850 as the build I'm going for isn't gonna need the 1000 watts. The XPG and Corsair RM 850W are 40$ less than the Corsair HX850 which is Platinum rated.)

[Guest]

3 hours ago, InfraDelta said:

For an extra 40$ is it worth to get a Platinum over a Gold or is Gold good enough?
(Looking into buying a new rig with either a Seasonic Focus GX Gold 1000watts or Seasonic Focus+ Platinum 850PX, then got recommended XPG Core Reactor 750w/850w, Corsair RM750x and Corsair HX750/850 as the build I'm going for isn't gonna need the 1000 watts. The XPG and Corsair RM 850W are 40$ less than the Corsair HX850 which is Platinum rated.)

This is a very old thread.  You should start a new one asking for advice.