*Reference* - Modern PC Power Requirements

[JEDIYoda]

Originally posted by: MrOblivious
Actually no. You already knew who I was as John and I discussed it previously on the forums and typically using the I know so becuase I do xy y or z is considered bad form. So instead I made my points for you to consider.

As for the rest I had simple observations and a difference of opinion sorry you can't see past it. I act in no official capacity beyond my own curiosity here or elsewhere beyond my employ and have participated in this area for some time on a number of forums.

Actually no he didn`t know who you were...not to discount the fact that some of us wante to make sure others know.....

call it what you will....
opinion s are like ...well you know...everybody has one...
suffice it to say without facts or references opinions can be interpreted any number of ways....

Peace!!

 

[tomoyo]

THANK YOU FOR THIS POST!

It just helps me explain why all those 600W+ psu's are completely pointless and in the land of retardation.
The best proof here is that non-sli systems can almost always easily run on a good 300 Watt psu. I just wish people would actually listen to that. Even sli systems don't usually need more than around 500 Watts unless you have something crazy.

The saying just goes, DON'T BUY OVERKILL PSUS PLEASE. I'm going to preach this until all those manufacturers making pointless 1600W psu's for massive profits finally give up their foolish notions. I just *cough* noticed an interesting trend on hardocp's psu reviews...there's quite a few BS overkill psu's reviewed there and very few sensible ones. Only the Corsair 450 and Seasonic 500 go into the range of sensible recently.



And Mr. Fox, I think your data is great and very helpful, don't let a few people who act as kneebiters get in your way. The goal in this study is to find what the maximum usage is and rate what a sensible GOOD QUALITY psu should be sized at. Nobody should ever care about crap psu's that derate quickly or have other completely terrible issues. A Good PSU should be extremely happy running at 75% load for 3-5+ years, if not, then it is complete and utter junk and should be thrown in the trash

Everyone go buy those Seasonics, Zippys, Andysons and whatnot!

 

[Yellowbeard]

Originally posted by: tomoyo
THANK YOU FOR THIS POST!

It just helps me explain why all those 600W+ psu's are completely pointless and in the land of retardation.

Well, keep in mind a couple of things here. I agree with you for the most part but, there are a few more factors to consider. I realize that there is a "fudge factor" built in here already but, this test does not specifically take individual systems into account.

So, let's take the worst case scenario of the 8800GTS in SLI ( Crossfire w/2 x 2900s will add about 60w over this estimate) which is estimated at 670w. Now, let's add in 2 cold cathodes, 2 more HDs, 4 DIMMs instead of 2, OC it to a moderate OC, add water cooling, add a couple more case fans, etc, then you have a substantial power draw. Also, most well designed PSUs seem to be their most efficient at about 65% of their max capacity.

And, you don't want a PSU running WFO 24/7. So, buying a bit more PSU than you "need" does have some merit. And, there is an admittedly small percentage of enthusiasts that will "need" some of the small nuclear reactors.

 

[tomoyo]

Originally posted by: Yellowbeard

Originally posted by: tomoyo
THANK YOU FOR THIS POST!

It just helps me explain why all those 600W+ psu's are completely pointless and in the land of retardation.

Well, keep in mind a couple of things here. I agree with you for the most part but, there are a few more factors to consider. I realize that there is a "fudge factor" built in here already but, this test does not specifically take individual systems into account.

So, let's take the worst case scenario of the 8800GTS in SLI ( Crossfire w/2 x 2900s will add about 60w over this estimate) which is estimated at 670w. Now, let's add in 2 cold cathodes, 2 more HDs, 4 DIMMs instead of 2, OC it to a moderate OC, add water cooling, add a couple more case fans, etc, then you have a substantial power draw. Also, most well designed PSUs seem to be their most efficient at about 65% of their max capacity.

And, you don't want a PSU running WFO 24/7. So, buying a bit more PSU than you "need" does have some merit. And, there is an admittedly small percentage of enthusiasts that will "need" some of the small nuclear reactors.

Very true that there are some systems that will certainly need a lot of power. In any sli scenario with the top end cards, you are looking at something needing a lot more power.
All the systems I've dealt with have been measured with a load power usage of under 275W. For those who actually have SLI setups, certainly the 750w psu's are useful. Of course even than, I can't imagine 1600w... And the other major thing to note, most computers are in idle or semi-idle most of the time. It's pretty rare to have a pc at full load on every core for an extended period of time.

But the extreme majority of computer makers don't have the budget or need for anything SLI/Crossfire in the first place. The percentage of SLI/crossfire buyers is still only 1.19%(at least according to valve steam stats). I'm sure it's higher at a place like anandtech, but it's still small. SLI/Crossfire just doesn't make money or energy sense for most people. I'm looking at the majority of people who have a basic non-sli system and have been tricked into thinking anything under a 600W psu is "too weak". A Corsair 450W is perfect for most people's needs.

 

[Mr Fox]

Originally posted by: tomoyo

Originally posted by: Yellowbeard

Originally posted by: tomoyo
THANK YOU FOR THIS POST!

It just helps me explain why all those 600W+ psu's are completely pointless and in the land of retardation.

Well, keep in mind a couple of things here. I agree with you for the most part but, there are a few more factors to consider. I realize that there is a "fudge factor" built in here already but, this test does not specifically take individual systems into account.

So, let's take the worst case scenario of the 8800GTS in SLI ( Crossfire w/2 x 2900s will add about 60w over this estimate) which is estimated at 670w. Now, let's add in 2 cold cathodes, 2 more HDs, 4 DIMMs instead of 2, OC it to a moderate OC, add water cooling, add a couple more case fans, etc, then you have a substantial power draw. Also, most well designed PSUs seem to be their most efficient at about 65% of their max capacity.

And, you don't want a PSU running WFO 24/7. So, buying a bit more PSU than you "need" does have some merit. And, there is an admittedly small percentage of enthusiasts that will "need" some of the small nuclear reactors.

Very true that there are some systems that will certainly need a lot of power. In any sli scenario with the top end cards, you are looking at something needing a lot more power.
All the systems I've dealt with have been measured with a load power usage of under 275W. For those who actually have SLI setups, certainly the 750w psu's are useful. Of course even than, I can't imagine 1600w... And the other major thing to note, most computers are in idle or semi-idle most of the time. It's pretty rare to have a pc at full load on every core for an extended period of time.

But the extreme majority of computer makers don't have the budget or need for anything SLI/Crossfire in the first place. The percentage of SLI/crossfire buyers is still only 1.19%(at least according to valve steam stats). I'm sure it's higher at a place like anandtech, but it's still small. SLI/Crossfire just doesn't make money or energy sense for most people. I'm looking at the majority of people who have a basic non-sli system and have been tricked into thinking anything under a 600W psu is "too weak". A Corsair 450W is perfect for most people's needs.

Well you should always error to the side of safety. But yes a 1600 watt PSU is a product with out a market at this point unless you go dual Barcs and SLI or some other exotic hardware w/a cigarette lighter.

 

[bryanW1995]

Originally posted by: MrOblivious

Liek I sadi I wasn't trying to bag on you but you are overestating your postion here.


"Fluke 434 is a very expensive piece of equipment ($4400.00) that is used industrially, and picks up peaks and transients and can data log, and do SPC etc. etc... etc... We use it to assure CNC and Robotic Computers are getting proper clean power, and also to study power savings incentives, preventive maintenance,etc "

That's nice and all but seriously going from experience I'll tell you transeint loads of 10ms or less are generally missed even by really expensive brand name units.

"Quality PSU's are rated at 50c ... I cannot control or dictate what some one does with the data, but if you buy based upon my study there is a good safety factor there. "

Then why does Seasonic rate at 40c, Zippy/Emacs at 45c?

"The 33% factor takes Max. Observed Peak Value and factors in the DeRating Curve for RubyCon PSU Capacitor Technical Data that is located here : RubyCon PSU Capacitors Design Data
RubyCon makes the best Capacitors.
All of the Quality Japanese Capacitors are basically the same Per IEEE standards.
So there is nothing "Nebulous" in my Data or my Recommendations. "

Precisely the number comes from a shot in the dark based on on subset of data not representative of the whole.

It's not my stuff on the line so really if people want to cut things too close and I probably should have known that after jon tried to explain it nicely before that it would fall on deaf ears again.

Oh well. I tried politely pointing out the problems. Caryy on.

I find it odd that seasonic rates at 40c while corsair rates at 50c.

 

[Yellowbeard]

Originally posted by: bryanW1995 I find it odd that seasonic rates at 40c while corsair rates at 50c.

Of course I don't know specifically why their rating temperature is different from ours. However, it's just another little thing we have done differently in our specific design.

 

[bryanW1995]

Originally posted by: tomoyo

Originally posted by: Yellowbeard

Originally posted by: tomoyo
THANK YOU FOR THIS POST!

It just helps me explain why all those 600W+ psu's are completely pointless and in the land of retardation.

Well, keep in mind a couple of things here. I agree with you for the most part but, there are a few more factors to consider. I realize that there is a "fudge factor" built in here already but, this test does not specifically take individual systems into account.

So, let's take the worst case scenario of the 8800GTS in SLI ( Crossfire w/2 x 2900s will add about 60w over this estimate) which is estimated at 670w. Now, let's add in 2 cold cathodes, 2 more HDs, 4 DIMMs instead of 2, OC it to a moderate OC, add water cooling, add a couple more case fans, etc, then you have a substantial power draw. Also, most well designed PSUs seem to be their most efficient at about 65% of their max capacity.

And, you don't want a PSU running WFO 24/7. So, buying a bit more PSU than you "need" does have some merit. And, there is an admittedly small percentage of enthusiasts that will "need" some of the small nuclear reactors.

Very true that there are some systems that will certainly need a lot of power. In any sli scenario with the top end cards, you are looking at something needing a lot more power.
All the systems I've dealt with have been measured with a load power usage of under 275W. For those who actually have SLI setups, certainly the 750w psu's are useful. Of course even than, I can't imagine 1600w... And the other major thing to note, most computers are in idle or semi-idle most of the time. It's pretty rare to have a pc at full load on every core for an extended period of time.

But the extreme majority of computer makers don't have the budget or need for anything SLI/Crossfire in the first place. The percentage of SLI/crossfire buyers is still only 1.19%(at least according to valve steam stats). I'm sure it's higher at a place like anandtech, but it's still small. SLI/Crossfire just doesn't make money or energy sense for most people. I'm looking at the majority of people who have a basic non-sli system and have been tricked into thinking anything under a 600W psu is "too weak". A Corsair 450W is perfect for most people's needs.

all of my computers are at full load on every core 90% + of the time. However, I use a 520hx on my e6750 with no problems at all.

 

[imported_smilingcrow]

I?m not clear how the fluke was connected to the PC; are the measurements showing the AC power draw from the wall socket? I ask because in most tests looking at PC power consumption the values shown are AC power draw and some people don?t realise that power supplies are rated for DC output.
Therefore a System that consumes 300W AC with a power supply that is 80% efficient at that load is only outputting 240W DC. This misunderstanding is another reason why people over specify their power supply.

What Vcore did you use on the over-clocked CPUs?

Nice post, thanks for sharing the data.

 

[maluckey]

I find it odd that seasonic rates at 40c while corsair rates at 50c.

I don't.

Manufacturers are shameless. If the PSU fared badly in certain tests or in MTBF calculations, they just shift the testing parameters until it suits the bill that they want to sell. In physics, I've heard it called Fenaglers Constant.

There are some pretty well-known brands that have played this game. The truth comes out about the time their newer models are released. By that time, the enthusiast normally buys the latest for the newest build and relegates the "old" sytem to less demanding duties.

 

[tomoyo]

Originally posted by: maluckey

I find it odd that seasonic rates at 40c while corsair rates at 50c.

I don't.

Manufacturers are shameless. If the PSU fared badly in certain tests or in MTBF calculations, they just shift the testing parameters until it suits the bill that they want to sell. In physics, I've heard it called Fenaglers Constant.

There are some pretty well-known brands that have played this game. The truth comes out about the time their newer models are released. By that time, the enthusiast normally buys the latest for the newest build and relegates the "old" sytem to less demanding duties.

That's rather disappointing that Seasonic is not rating based on 50C, however I wouldn't call them shameless at all. Just imperfect. 40C IS a realistic number unlike those psu makers that a) Rate at 25C b) make psu's that explode. Those are the shameless makers that need to be put outta misery. They're also the makers that convince people that 600W psu's made from tinfoil are somehow better than a Seasonic 330W.

 

[tomoyo]

It seems these are AC input power measurements. This actually means the power used is likely 15-20% less than stated here on the DC side. Which means ALL non-sli systems actually are using UNDER 300 Watts. Everyone should take note of this and avoid overbuying your psus!!!

 

[conlan]

Mr Fox, thanks for sharing your hard work with the AT community. :thumbsup:

 

[tcsenter]

Originally posted by: Mr Fox
The other issue that Mr Johnson was pressing at was 33% and where I got that.
.3 happens to be the exact de-rate rule of thumb for a Tant. cap. @ 50 Deg C.
add to that : if the designer did his work properly there is 15-20% built in safety factor in the design bill of materials.

Not to mention the entire canard about 'transients' having any bearing on the discussion at all. You don't deal with high-speed transients in the PSU, anyhow. That should be dealt with as close to the source of the load as practical (e.g. on the PCB), using bulk output capacitance and/or other techniques such as voltage positioning.

In fact, there should be a moderate degree of decoupling between the PSU and whatever is happening transiently on the motherboard. The PSU needs to concern itself with the AC > DC regulation, while the PCB deals with DC > DC regulation, with little feedback or communication owing to transients betwixt them.

 

[JEDIYoda]

Originally posted by: tomoyo
It seems these are AC input power measurements. This actually means the power used is likely 15-20% less than stated here on the DC side. Which means ALL non-sli systems actually are using UNDER 300 Watts. Everyone should take note of this and avoid overbuying your psus!!!

why avoid ovr buying?
Ar people really over buying?
Do most 300watt PSU put out the required amps on the 12v rail to power todays top of the line hardware?
hmmmm

 

[tomoyo]

Originally posted by: JEDIYoda

Originally posted by: tomoyo
It seems these are AC input power measurements. This actually means the power used is likely 15-20% less than stated here on the DC side. Which means ALL non-sli systems actually are using UNDER 300 Watts. Everyone should take note of this and avoid overbuying your psus!!!

why avoid ovr buying?
Ar people really over buying?
Do most 300watt PSU put out the required amps on the 12v rail to power todays top of the line hardware?
hmmmm

Why avoid? To get better efficiency? To not waste money? To get a quieter psu?
And of course people are overbuying, they buy 600w when they need 250, they buy 750 when they need 400, it happens all the time.
See Seasonic S12-II 330, that can power almost any non-sli pc.

 

[rogue1979]

This was a goldmine of information, thanks for all the hard work.

I am currently using a Fortron Source 400-watt to power a 3200+@2.8GHz, X1900GT @580/1700, 320GB SATA, 4 fans, 2GB ram. It never even gets warm and all rails are rock solid.

I was wondering why people need 750-watt and higher power supplies? Well, unless you are running a Quad Core at over 3.0GHz with quad graphic cards, 4 hard drives, 4GB of ram, and a half a dozen fans, you don't!

 

[seemingly random]

Originally posted by: tomoyo
those manufacturers making pointless 1600W psu's for massive profits

There's an old saying that goes something like: "It's a sin to let a fool keep his money".

And another: "It's hard/fruitless to fight the tide".

 

[ArchAngel777]

Wow! Hats off to the OP's data!

 

[MyLeftNut]

Good research, at the right time too. I'm currently looking to get a new UPS for my system and judging from the data collected in this research, it gives me a good reference point for selecting a UPS. Right now I'm using a 550va/300W UPS with a system using a 650W PSU and it doesn't seem to be cutting it when loading a game and burning a DVD.