"How many watts do I need"? Check Here!

[Bhav]

5 minutes ago, Stefan Payne said:

Yeah and how many people have you met that actually do that?!

You know that Ampere is on the Horizon?!

You know how many Games don't support SLI/CF at all?! MOST!

 

Only if you play the AAA Hardcore Shooters you might get something out of a two GPU setup, but it just doesn't work with all those Japanese games. If Koei Tecmo is on the label, you can be certain it doesn't work or you don't need it anyway because of Framelock. 

 

So why propagate Bullshit that nobody uses anymore?!

This isn't the thread to argue about what people want to add to their PCs. There's nothing at all wrong about getting a decent 650 watt PSU at just $15 more if one wants to down such a route. He might simply want to mine. Also you can't completely guarantee how much power his future upgrades may require.

[Bhav]

29 minutes ago, Stefan Payne said:

 

Just going for the 650W doesn't give you any benefits at all. In some/many cases you get a higher rpm fan and so higher noise. Like the Bitfenix Whisper M where the fan was changed with the quad rail models. 

 

So you have 100W more, but not lower noise in many cases, because the plattforms are changed around 750W usually, sometimes 850W, you don't have better efficiency.

 

Just to point out that this particular PSU, and in fact most have variable RPM fans:

 

https://www.kitguru.net/components/power-supplies/zardon/seasonic-g-series-650w-power-supply-review/6/

 

The fan only speeds up to audible levels during the units last 100 wattage rating.

 

This is particularly true for the majority of PSUs - if you actually want a silent PSU, then you want one with additional wattage so that it doesn't end up heating up too much thus causing the fan to spin louder, or even one with an eco fan that may not need to switch on at all.

 

Also in terms of efficiency, PSUs are most efficient at 50% load, so if you going to argue the fact to specify a higher efficiency but lower wattage rating, this may not be the most ideal case for maximising the efficiency of a PSU.

[seon123]

44 minutes ago, Bhav said:

Just to point out that this particular PSU, and in fact most have variable RPM fans:

 

https://www.kitguru.net/components/power-supplies/zardon/seasonic-g-series-650w-power-supply-review/6/

 

The fan only speeds up to audible levels during the units last 100 wattage rating.

 

This is particularly true for the majority of PSUs - if you actually want a silent PSU, then you want one with additional wattage so that it doesn't end up heating up too much thus causing the fan to spin louder, or even one with an eco fan that may not need to switch on at all.

 

Also in terms of efficiency, PSUs are most efficient at 50% load, so if you going to argue the fact to specify a higher efficiency but lower wattage rating, this may not be the most ideal case for maximising the efficiency of a PSU.

All decent PSUs have variable speed fans. Take a look at Cybenetics' testing, the fact curve depends on the exact PSU in question.

https://www.cybenetics.com/index.php?option=database

 

A 500W PSU at a 300W load at 85% efficiency produces the same amount of heat as an 800W PSU at a 300W load at 85% efficiency. 

 

The difference in efficiency between a 50% load and a 100% load is 3%. That's nothing. 

[Stefan Payne]

1 hour ago, Bhav said:

Also you can't completely guarantee how much power his future upgrades may require.

I know more about the Future of PSU than you do so I know that buying for the Future is bullshit because you can't know anything about the future.

And another thing you should think about:
The IBM AT was released in 1984.

The ATX specification was releasted in 1995

1995 - 1984 = 11 Years

We have 2018 right now. That is 23 Years later.

And many business Computers already use +12V Only PSU! Some with a +5VSB rail, some even with a 12V standby rail...

 

So don't you think that its more probable that the ATX specification wil be replaced or reworked int he next couple of years??

 

And that is what is happening and people from Antec and Corsair are talking about at Jonnyguru's Forum. There are changes coming in 2020 that might render every PSU thats on the Market today useless with the upcoming components.

 

So stop your 'Buying for the Future' Nonsense. You buy it for the system you have right now, not for something that might or might not happen in the Future because you don't know the future!!

 

And with an i5-8400 its highly improbable that he will ever need 650W...

 

 

1 hour ago, Bhav said:

Just to point out that this particular PSU, and in fact most have variable RPM fans:

 

https://www.kitguru.net/components/power-supplies/zardon/seasonic-g-series-650w-power-supply-review/6/

 

The fan only speeds up to audible levels during the units last 100 wattage rating.

Dude, trying to tell me something about PSU is a mistake, if you aren't an engineer or working in the industry, you will just look silly.

How high a fan spins depends on the what the manufacturer of that unit wants and specifies.

 

Quote

This is particularly true for the majority of PSUs - if you actually want a silent PSU, then you want one with additional wattage so that it doesn't end up heating up too much thus causing the fan to spin louder, or even one with an eco fan that may not need to switch on at all.

That is utter nonsense again, you don't know nothing about PSU and are putting out false information on the Internet, while you didn't do your homework.

Here some information for you:
https://www.hardwareluxx.de/community/f238/quiet-straight-power-11-mit-kabellosem-innendesign-startet-1189012-2.html#post26097698

 

Click on that link and on the picture.

Those are from the manufacturer and about the Dark Power Pro P10.

The rpm of the 550W Dark Power P10 spins lower at 100% load than the 650W at 10%.

550-750W use one Plattform in this case, 850-1200W use another one. That didn't change for the Dark Power P11 series.

 

So your claim that you should have some 'room' for the PSU to be quiet is just false. There is no actual basis for that.

Actually it seems its quite the opposite: Lower wattage PSU can be quieter than higher wattage ones.

Quote

Also in terms of efficiency, PSUs are most efficient at 50% load, so if you going to argue the fact to specify a higher efficiency but lower wattage rating, this may not be the most ideal case for maximising the efficiency of a PSU.

Again, your claim is wrong. PSU don't are most efficient at 50% load in general, you have to look at the PSU you want and look at a measured efficiency diagram measured in 10% steps at least, better 5%. And then you see that many PSU are more efficient under 50% load.

 

Here a couple of examples:
Corsair AX1600i, most efficient at around 20-40% at 50% it already lost almost a whole percent:
At 230VAC it looks even worse. Peak is also around 30% but stays around 95% from 20 to 70% load

http://www.tweakpc.de/hardware/tests/netzteile/corsair_ax1600i/s03.php

 

be quiet Straight Power 10, 750W Version

Peak efficiency around 30-40%, already lost a bit at 50% and its about the same on 230VAC

http://www.tweakpc.de/hardware/tests/netzteile/be_quiet_straight_power_11/s03.php

 

So your claim that PSU are most efficiency at 50% load is also proven to be false.

As is every other claim you made about PSU so far.

 

So a 650W offers over a 550W only 100W more, nothing more, nothing less!

Some units are louder lower load and about the same at higher loads.

And they cost more

 

So what benefit do you get for the money? If you don't need the wattage, NOTHING!

So a 650W (IMO the worst wattage of them alle because the most useless -> too little for multi GPU, too much for single GPU) offers no benefit at all.

 

Only if we are talking about two completely different units then the higher wattage can be better - but its almost never the case at 550 to 650W and either at 650 to 750W or 750 to 850W, depending on the Wattages of the units and plattforms used. Then the higher wattage unit can be beneficial in many aspect but because its a completely different unit! 

The Examples I can think of right now:
be quiet Dark Power Pro P10 and P11 -> Change from 750 to 850W

Corsair RM (all), change from 650 to 750

 

Bitfenix uses the same plattform for all Whisper M and one Plattform for all Formula series PSU but uses different fans

Seasonic also tends to use the same platform for all but also uses the same fan for a series. In this case higher efficiency can be beneficiary and make the PSU quieter!

 

[Bhav]

@Stefan Payne

 

Post links that are in English or don't bother. What I claimed is backed by Linus, Johnnyguru, and Kitguru to name just a few, and has been well evidenced and documented since the dawn of fully reviewing PSUs, as well as the literal 80 plus specifications that all PSUs must meet to achieve those ratings. 

 

I'll take their word over someone thats so easily angered and constantly types rubbish all over this forum.

 

And here's one such link from a quick Google search confirming what I claimed is correct:

 

http://www.tomshardware.co.uk/forum/328652-28-true-psus-efficiency-load

 

[seon123]

1 minute ago, Bhav said:

Post links that are in English or don't bother. What I claimed is backed by Linus, Johnnyguru, and Kitguru to name just a few, as well as the literal 80 plus specifications that all PSUs must meet to achieve those ratings.

 

I'll take their word over someone thats so easily angered and constantly types rubbish all over this forums.

Feel free to come with actual arguments and sources, and not just an appeal to authority. 

You don't have to know a language to read numbers. 

[Bhav]

8 minutes ago, seon123 said:

Feel free to come with actual arguments and sources, and not just an appeal to authority. 

You don't have to know a language to read numbers. 

Posted a link that confirms my claims, but all you literally had to do was simply read the 80 plus efficiency criteria.

 

That can be found here:

 

https://en.m.wikipedia.org/wiki/80_Plus

 

All 80 plus PSUs MUST reach those targets to get qualified as such, which means highest efficiency at 40-60% load. If any individual, or specific type / brand of PSU doesn't, then it's simply failing this criteria and should not have been classified as 80 plus in the first place.

[Bhav]

Proof for higher wattage PSUs remaining cooler can be found right here:

 

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=462

 

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=459

 

The 850 watt unit running at 855 watts has intake / exhaust temps of 51 / 61 degrees C.

 

The 1000 watt unit running at 806 watts has intake / exhaust temps of 42 / 56 degrees C, and only reaches the same figures as the 850 watt unit when running at 1000 watts.

[seon123]

4 minutes ago, Bhav said:

Posted a link that confirms my claims, but all you literally had to do was simply read the 80 plus efficiency criteria.

The highest efficiency number was at 270W, at a 42% load. 

The noise level at a 100% load was measured to be 34dBA, that's quite a bit lower than most 650W units. 

It was not compared to any other PSU, so you have no grounds to compare it to other wattages. 

80+ ratings are a requirement. It does not mean that a PSU will be that efficient at their loads. It is a minimum requirement to get certified. A PSU could be 95% efficient at a 25% load and 94% efficient at a 50% load, and it would still get the same 80+ Titanium certification.

[Stefan Payne]

9 minutes ago, Bhav said:

@Stefan Payne

 

Post links that are in English or don't bother. What I claimed is backed by Linus, Johnnyguru, and Kitguru to name just a few, and has been well evidenced and documented since the dawn of fully reviewing PSUs, as well as the literal 80 plus specifications that all PSUs must meet to achieve those ratings. 

ORLY?!

Lets ask @jonnyGURU

Where is the PSU most efficient? Is it at around 45-55% or is it somewhere else? Or dou you just not care when makeing a PSU where the peak Efficiency is and it just happen to be where it is where it is? (wich would be my guess).

 

And I've already posted the important numbers here, the Links are just to link to my sources. So you don't need to know German because I've already provided you with Numbers.

 

But since you asked so nicely, here some more numbers:

Enermax MaxTytan im Test - Schönheit mit Titanium Effizienz  - Effizienz und Leistungsdaten (3/10) Enermax MaxTytan
Seasonic Focus+ 650W Gold, 30%
Corsair HX750W, 40% und schau dir mal an, wie flach die Effizienz "Kurve" auf 230VAC ist.
Das von dir verlinkte Pure Power ist auch bei 30% Last am Effizientesten
Cooler Master V550S, bei 20% am effizientesten!
Chieftec Proton 1000W, 30%
750W Proton, 30-40%
Chieftec Power Smart, 40%
1000W Leadex II, 30%
 

Translation: am effizientesten -> Most efficient

 

And all of those are well below 50% load and more in the 30-40% range for the peak.

 

But that doesn't really matter much because what are we taltking about? 2% or something like that??

 

 

9 minutes ago, Bhav said:

I'll take their word over someone thats so easily angered and constantly types rubbish all over this forum.

So you take the word of some people, somewhere on the Interwebs instead of actual numbers provided by a person measuring those on a Chroma ATE Teststation??

 

So in other Words you don't care about facts, you care about feelings??

 

 

9 minutes ago, Bhav said:

And here's one such link from a quick Google search confirming what I claimed is correct:

http://www.tomshardware.co.uk/forum/328652-28-true-psus-efficiency-load

...wich was proven wrong by actual numbers, measurured by an actual person.

 

 

You can feel free to search the Techpowerup Reviws. I also did that at one time. That's in English.

But do you really think that that will change at all?!

 

 

 

 

[Stefan Payne]

2 minutes ago, Bhav said:

Proof for higher wattage PSUs remaining cooler at the same loads incoming here

How should that work?!

Have you ever head of the rules of thermodynamics?
 

How can a higher wattage PSU be cooler, when it has the same heatsinks, about the same efficiency?!

Oh right, higher Fan RPM, of course.

 

[Bhav]

2 minutes ago, Stefan Payne said:

How should that work?!

Have you ever head of the rules of thermodynamics?
 

How can a higher wattage PSU be cooler, when it has the same heatsinks, about the same efficiency?!

Oh right, higher Fan RPM, of course.

 

The info is added now, you can see it.

 

Both the reviews also confirm those PSUs are most efficient (close to 94%) at 50% load.

 

Now it's your turn to debunk all these figures if you want to prove that I am not posting correct information.

 

And no, I am very certain that both those units use the same fan.

[Stefan Payne]

15 minutes ago, Bhav said:

Posted a link that confirms my claims, but all you literally had to do was simply read the 80 plus efficiency criteria.

 

That can be found here:

 

https://en.m.wikipedia.org/wiki/80_Plus

 

All 80 plus PSUs MUST reach those targets to get qualified as such, which means highest efficiency at 40-60% load. If any individual, or specific type / brand of PSU doesn't, then it's simply failing this criteria and should not have been classified as 80 plus in the first place.

Yeah and 80plus is useless for this argument because they only have 3 points they measure at: 20% load, 50% load and 100% Load.

With newer ones there was a fourth. 10% load. 

 

So that is why those are useless: They don't provide much data to come to a conclusion. ANd with their data it looks like peak efficiency is at 50% - wich it is, when you don't measure between 20 and 50% load, wich is what TweakPC and others did. And according to those numbers, the Peak Efficiency of PSU is somewhere between 30% and 60% load or so.

 

And with 230VAC it doasn't even matter because there isn't even a curve but more like a line for the efficiency...

[seon123]

9 minutes ago, Bhav said:

Proof for higher wattage PSUs remaining cooler can be found right here:

 

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=462

 

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=459

 

The 850 watt unit running at 855 watts has intake / exhaust temps of 51 / 61 degrees C.

 

The 1000 watt unit running at 806 watts has intake / exhaust temps of 42 / 56 degrees C, and only reaches the same figures as the 850 watt unit when running at 1000 watts.

Well, since the delta temperature for the 850W unit is 10°, and it's 14° for the 1000W unit, that doesn't exactly help prove your point. 

[Bhav]

Just now, Stefan Payne said:

Yeah and 80plus is useless for this argument because they only have 3 points they measure at: 20% load, 50% load and 100% Load.

With newer ones there was a fourth. 10% load. 

 

So that is why those are useless: They don't provide much data to come to a conclusion. ANd with their data it looks like peak efficiency is at 50% - wich it is, when you don't measure between 20 and 50% load, wich is what TweakPC and others did. And according to those numbers, the Peak Efficiency of PSU is somewhere between 30% and 60% load or so.

 

And with 230VAC it doasn't even matter because there isn't even a curve but more like a line for the efficiency...

Again, these figures were tested, proven as such, and documented on both the reviews I posted, both those EVGA T2 PSU are proven by Johnnyguru to be most efficient at 50% load, unless you are claiming that he is lying.

[Bhav]

5 minutes ago, seon123 said:

Well, since the delta temperature for the 850W unit is 10°, and it's 14° for the 1000W unit, that doesn't exactly help prove your point. 

All we are talking about in this regard is fan RPM and noise, nothing else.

 

In the 1000 watt unit test, the fan doesn't even switch on until 6 minutes into the 800+ watt load test, logically confirming that even once it does, it's only going to be spinning at its minimum fan curve.

 

In the 850 watt unit test, the fan is logically going to have to be spinning much faster, and thus louder at the same load as the temps are around 10 degrees higher.

 

Initial post was more thorough, but I'm not typing it all out again.

[Stefan Payne]

 

1 minute ago, Bhav said:

Again, these figures were tested, proven as such, and documented on both the reviews I posted, both those EVGA T2 PSU are proven by Johnnyguru to be most efficient at 50% load, unless you are claiming that he is lying.

Yes, and?
That is one unit.

I provided you with Infos about 11 other units. 

 

Yes, there are some PSU that happen to have the Peak Efficiency at around 50%. That doesn't prove you are correct because you claimed that for ALL PSU. For wich it is not correct. And I've proven my point with Links to two units in the begining and at a later point 9 additional units.

 

 

How the heck cal you still claim that the peak Efficiency of PSU is at 50% when it is not?? It is somewehere, mostly between 20 and 50% load...

But on older Planet 3DNow Tests from 2005/6 (or was it 6/7??) the Peak Efficiency was above 50%. 

You can't see that if you don't measure those points...

[Bhav]

22 minutes ago, Stefan Payne said:

 

Yes, and?
That is one unit.

I provided you with Infos about 11 other units. 

 

Yes, there are some PSU that happen to have the Peak Efficiency at around 50%. That doesn't prove you are correct because you claimed that for ALL PSU. For wich it is not correct. And I've proven my point with Links to two units in the begining and at a later point 9 additional units.

 

 

How the heck cal you still claim that the peak Efficiency of PSU is at 50% when it is not?? It is somewehere, mostly between 20 and 50% load...

But on older Planet 3DNow Tests from 2005/6 (or was it 6/7??) the Peak Efficiency was above 50%. 

You can't see that if you don't measure those points...

So those 11 units are not 80 plus units and should not have been given that classification, I already stated that.

 

It's not my fault if PSUs are being falsely classified and marketted.

 

I claimed for PSUs to be valid for 80 plus certification, not 'all PSUs'. Please read better.

 

Anyone can confirm this by reading the reviews. If a PSU is 80 plus rated but does not meet 80 plus efficiency requirements, then simply don't buy or recommend it. Johnny guru would clearly mention that such a unit has failed it's 80 plus classification and likely rate it as a dumpster trash tier PSU.

 

All you are proving is that PSUs that are not / should not be 80 plus rated are not reaching 80 plus required efficiency figures, which is 100% pointless and not supporting any of your claims nor disproving mine.

 

FACT FACT FACT - ALL VALID ***80 PLUS RATED*** PSUs MUST BE MOST EFFICIENT AT (around) 50% LOAD - FACT FACT FACT

 

EG

 

 

Another 80 plus PSU that is most efficient at around 40-60% load:

 

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=374

 

 

Quote

How the heck cal you still claim that the peak Efficiency of PSU is at 50% when it is not?? It is somewehere, mostly between 20 and 50% load...

 

Erm, even 20-50% includes 50% FYI, and for such a unit, only confirms my claim that you should buy a higher rated PSU that you will be able to keep within 20-50% usage to maximise energy efficiency.

 

So you aren't even disproving anything I have stated, only confirming that I was indeed correct, and you yourself were false and purposefully lying all along.

 

So for such a PSU, if you want maximum energy efficiency, you want to OVERSPECIFY a PSU that will mostly run at 20-50%,  NOT buy a minimum rated PSU for your usage that will be running at 80% plus (which will not only be less efficient,  but also generate much more fan noise from higher temps). 

[mariushm]

29 minutes ago, Bhav said:

FACT FACT FACT - ALL VALID ***80 PLUS RATED*** PSUs MUST BE MOST EFFICIENT AT 50% LOAD - FACT FACT FACT

No, that's not correct.

 

80 Plus requires that the power supply reaches some efficiency at some threshold. It doesn't say "don't go over it"

So some power supply may be let's say 85.5% efficient at 50% (good enough for 80 plus bronze) but could be 87% efficient at 70% load for example and then go down.

Some manufacturers can take a 80plus Gold model and replace some components to make a cheaper version and that version may still be capable of 80plus Silver, but because people are stupid and are confused about "Silver" (look at stores, there's barely any Silver rated psus), they may simply sell it as Bronze... or the power supply can't do the output power at 50c ambient, so they derate it for 40c max and call it bronze efficiency ... in such cases efficiencies may be skewed. 

 

There's power supplies like this 1500w one, which peak at around 300-400w and then the efficiency goes down all the way to 1600w .. so at 50% it's not the most efficient ... yet this psu is rated 80 plus gold : http://www.tomshardware.com/reviews/silverstone-strider-titanium-st1500-ti-psu,5324-5.html

 

Or this EVGA Supernova G3 ... 1000w but peaks at around 300w, which is not 50% : http://www.tomshardware.com/reviews/evga-supernova-1000-g3-psu,4941-5.html

 

Or that 1000$ cooler master made in japan psu rated for 1200w, it peaks at 94% efficiency at around 500w (not 50%) : http://www.tomshardware.com/reviews/cooler-master-masterwatt-maker-1200-mij-psu,4963-5.html

 

Here's for example EVGA B3 450w, which has the highest efficiency at around 250-300w, which is higher than 50% : http://www.tomshardware.com/reviews/evga-450-b3-psu,5160-5.html

Or the EVGA B3 850w psu, which peaks at around 500w with almost 88% efficiency, even though it's bronze rated and only needs to reach 85% at 50% :

 

[Bhav]

I'm reading as many PSU reviews as I can, and I think you had my claims confused other a unit such as this one:

 

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=539

 

To confirm what I mean, under 80 plus classification it is not specifically necessary that a PSU is *maximum efficiency* at 50*, but the base standard REQUIRES maximum efficiency to be at the 50% point.

 

If a unit such as this Corsair one maintains the same efficiency for 80 plus at 50% outside of this range (any such case seems so far to be at a lower use, like 20-50%), then obviously this is an even better unit, I am not at all disputing that.

 

However, the efficiency at 50% usage CANNOT BE BELOW (or for the sake of fairness, more than 1% below as per johnnyguru's tolerance levels) the 80 plus criteria.

 

As such, all this does is in fact confirm that OVER SPECIFYING the PSU wattage on such a unit that will run at 20-50% in your system WILL GIVE YOU THE MOST ENERGY EFFICIENCY, and run cooler and quieter than running a lower wattage PSU at 80%+ load.

[Bhav]

5 minutes ago, mariushm said:

No, that's not correct.

 

80 Plus requires that the power supply reaches some efficiency at some threshold. It doesn't say "don't go over it"

Right, what I meant to say would be that it's a fact that the MINIMUM standards for 80 plus dictate that the highest efficiency be obtained at 50% load. I did not mean, and it is entirely unintentional if it sounded like I was saying that PSUs cannot exceed those 80 plus standard figures. What I thought Stefan was implying is that a PSU might be LESS efficient at 50% than the 80 plus criteria requires.

 

If a PSU is above the efficiency criteria at all levels, then that is only better, and only goes to prove my initial claim that over specifying a PSU will give you better efficiency and lower temps / noise, which is exactly hat Stefan is trying to argue against.

 

Nothing I have claimed here is false, nor has it been disproven, only further supported.

 

 

[mariushm]

1 minute ago, Bhav said:

To confirm what I mean, under 80 plus classification it is not specifically necessary that a PSU is *maximum efficiency* at 50*, but the base standard REQUIRES maximum efficiency to be at the 50% point.

No, it requires that power supplies REACH or EXCEED some efficiency threshold at some load levels (20%, 50%, 100% and 10% for titanium).

The power supply may hit higher efficiency and it may be even be possible or good enough to classify the power supply at a higher level (silver instead of bronze for example), but if the manufacturer wants to call it Bronze, he's free to do so.

 

See table below.

So for example a bronze efficiency power supply must reach or exceed 82% at 20% load if powered from 115v (US plugs) AND reach and exceed 85% at 20% when powered from 230v... and so on.

 

80 Plus test type[4]	115V internal non-redundant								230V EU internal non-redundant
Percentage of rated load	10%	20%	50%	100%					10%	20%	50%	100%
80 Plus		80%	80%	80%						82%	85%	82%
80 Plus Bronze		82%	85%	82%						85%	88%	85%
80 Plus Silver		85%	88%	85%						87%	90%	87%
80 Plus Gold		87%	90%	87%						90%	92%	89%
80 Plus Platinum		90%	92%	89%						92%	94%	90%
80 Plus Titanium	90%	92%	94%	90%					90%	94%	96%	94%

[Bhav]

1 minute ago, mariushm said:

No, it requires that power supplies REACH or EXCEED some efficiency threshold at some load levels (20%, 50%, 100% and 10% for titanium).

The power supply may hit higher efficiency and it may be even be possible or good enough to classify the power supply at a higher level (silver instead of bronze for example), but if the manufacturer wants to call it Bronze, he's free to do so.

 

See table below.

So for example a bronze efficiency power supply must reach or exceed 82% at 20% load if powered from 115v (US plugs) AND reach and exceed 85% at 20% when powered from 230v... and so on.

 

80 Plus test type[4]	115V internal non-redundant								230V EU internal non-redundant
Percentage of rated load	10%	20%	50%	100%					10%	20%	50%	100%
80 Plus		80%	80%	80%						82%	85%	82%
80 Plus Bronze		82%	85%	82%						85%	88%	85%
80 Plus Silver		85%	88%	85%						87%	90%	87%
80 Plus Gold		87%	90%	87%						90%	92%	89%
80 Plus Platinum		90%	92%	89%						92%	94%	90%
80 Plus Titanium	90%	92%	94%	90%					90%	94%	96%	94%

 

Key words in what you quoted - 'base standard requires'. It's not at all a problem, and only further supporting my initial claims if a PSU EXCEEDS 80 plus figures.

[Bhav]

E.G. If my EVGA T2 1000w never hits 800 watt usage, the fan won't even switch on (as per it's review on Johnnyguru), and the efficiency level will be higher.

 

If I used a PSU that was let's say 550w, and my PC uses all of that, then it's running at its least possible efficiency, generating much more heat, and the fan needs to spin at its maximum.

 

Also if all PSUs output the same heat / need the same cooling at the same wattage, then how exactly is my PSU keeping itself passively cooled with the fan switched off while under 800 watts and staying under 50 degrees, while a 550 watt unit would need it's fan spinning at max to dissipate it's heat at maximum load and be running over 60 degrees? 

[mariushm]

47 minutes ago, Bhav said:

E.G. If my EVGA T2 1000w never hits 800 watt usage, the fan won't even switch on (as per it's review on Johnnyguru), and the efficiency level will be higher.

 

Yeah, because the fan doesn't use 1-2 watts to spin. Congrats, you improved efficiency by 0.01% and you have a silent PC but you're keeping your power supply much hotter in return.

 

47 minutes ago, Bhav said:

Also if all PSUs output the same heat / need the same cooling at the same wattage, then how exactly is my PSU keeping itself passively cooled with the fan switched off while under 800 watts and staying under 50 degrees, while a 550 watt unit would need it's fan spinning at max to dissipate it's heat at maximum load and be running over 60 degrees? 

Basic physics and economics dude.

 

The 550w power supplies have to be sold at some price, there's bigger competition in that segment compared to 1000w and up market where manufacturers can charge more.

 

You can't compare the electronics of a 550w psu with the electronics of a 1000w psu... it's apples to oranges.

The 550w model may use switching transistors and mosfets rated for only 125c which means the psu has to be cooled enough to keep them at below ~90c for safety. A 1000w psu may use higher quality mosfets with lower losses with 150c rating or even higher, which means they may run them up to 110-120c - this means it's possible to use smaller heatsinks, or cut the fan at lower wattages where the mosfets don't dissipate much heat.

 

The transformer on a 550w psu is smaller than the one on a 1000w psu , it has less mass, it's harder to cool... it's probably also a cheaper design or one that's less carefully constructed (very mass produced to save cost and using same model for various models even though its not ideal, to save costs) which means it may be less efficient and heats more. They probably have to keep the internal temperature to around 70-80c otherwise the insulation on the wires inside may break. A 1000w psu would have potentially a bigger transformer easier to cool and maybe better constructed one, and with double insulated wires and all that jazz, and potentially could work at even 100c again allowing for less cooling.

 

A 550w power supply may use smaller heatsinks relying on air flow (forced air cooling) to maintain the temperatures low on the secondary side. Weight adds to the shipping costs and the material is not free. Sometimes pennies in savings add up.

Cooling is material (copper better than aluminum etc), mass (thickness, size) and surface (anodized or not, balance between size and how many fins and how spaced apart they are and so on) but also AIR FLOW ... if you force air through fins of a heatsink, the heatsink's performance increases.

So the less efficient components on the 550w model may produce more heat, but the 550w psu may have bigger heatsinks (because the 1000w psu may have to squeeze more components on the circuit board leaving little room for heatsinks) and also keeps the temperatures low by blowing more air over the bigger heatsinks.

 

There's all kinds of trade-offs.