1KW and above PSUs Why?

[Format _C:]

Soon my computer will need to be on a dedicated circuit breaker if the PSUS get anymore powerful. My Question why is power use going up not down? I would think with all of the miniaturization of parts (CPU Cores HDDS Etc) that the heat output would go down and so would the power consumption of the newer parts Does any one have any input of this subject?

 

[skadebo]

Well here is some insight: http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3222

Basically, most people don't need them. It's a flagship model by companies aimed at gaining brand recognition. Like the Bugatti Veyron.

 

[Sunin]

Well considering a Single GTX system uses something like 230-250w, and a second system pushes that in excess of 400-450w, adding HDs, sound cards, etc can make it easily breach 500 plus watts and I wanted a 1kw unit to never EVER have to worry about having some damned clean power that I could run 24/7 without worries.

Silverstone's 1kw unit ran me just about $300 and its pretty future proof. I expect to have it for 10 plus years.

 

[Menelmarar]

Well considering a Single GTX system uses something like 230-250w, and a second system pushes that in excess of 400-450w, adding HDs, sound cards, etc can make it easily breach 500 plus watts and I wanted a 1kw unit to never EVER have to worry about having some damned clean power that I could run 24/7 without worries.

Silverstone's 1kw unit ran me just about $300 and its pretty future proof. I expect to have it for 10 plus years.

They'll likely change the power connectors on you before then.

Buddy of mine stupidly anal like you, bought a 1200W power supply a few years ago for like $300, had the old 20pin connector. Built a new system recently, bought yet another power supply due to the new 24pin connectors, new pcie power connecters, new sata power connectors, etc. Iolled.

 

[[Spectre]]

Soon my computer will need to be on a dedicated circuit breaker if the PSUS get anymore powerful. My Question why is power use going up not down? I would think with all of the miniaturization of parts (CPU Cores HDDS Etc) that the heat output would go down and so would the power consumption of the newer parts Does any one have any input of this subject?

Power supplies only output the amount of power the system draws, they do not output their full capacity at all times.

 

[Arcygenical]

Well considering a Single GTX system uses something like 230-250w, and a second system pushes that in excess of 400-450w, adding HDs, sound cards, etc can make it easily breach 500 plus watts and I wanted a 1kw unit to never EVER have to worry about having some damned clean power that I could run 24/7 without worries.

Silverstone's 1kw unit ran me just about $300 and its pretty future proof. I expect to have it for 10 plus years.

The combined wattage from all 3 systems in sig is roughly around 600w... Measured at the wall, so approximately 500w from the PSU.

Unless you're running Quad SLI, there's no reason to have over 700w...

 

[[Spectre]]

The combined wattage from all 3 systems in sig is roughly around 600w... Measured at the wall, so approximately 500w from the PSU.

Kill-A-Watt?

Unless you're running Quad SLI, there's no reason to have over 700w...

There are plenty of reasons.

 

[Sunin]

They'll likely change the power connectors on you before then.

Buddy of mine stupidly anal like you, bought a 1200W power supply a few years ago for like $300, had the old 20pin connector. Built a new system recently, bought yet another power supply due to the new 24pin connectors, new pcie power connecters, new sata power connectors, etc. Iolled.

If I recall from the wording, for $15 bucks you can send your silverstone back to them and they will rewire it.

Thought of that already.

Also look at [H]'s PSU reviews and see how the power supplies fair at 50% of power usage versus 100% related to efficiency, power variance and heat for that matter. There is a reason!

 

[Dan_D]

Soon my computer will need to be on a dedicated circuit breaker if the PSUS get anymore powerful. My Question why is power use going up not down? I would think with all of the miniaturization of parts (CPU Cores HDDS Etc) that the heat output would go down and so would the power consumption of the newer parts Does any one have any input of this subject?

As a general rule more power is required for technology as it advances. Not less. Somethings are more power efficient and do use less energy, but not always. Certainly in regard to computer equipment power requirements for devices has gone up. I think hard drives require less power and memory tends to use less power. Motherboards, processors, and video cards have gone the other way though.

Well considering a Single GTX system uses something like 230-250w, and a second system pushes that in excess of 400-450w, adding HDs, sound cards, etc can make it easily breach 500 plus watts and I wanted a 1kw unit to never EVER have to worry about having some damned clean power that I could run 24/7 without worries.

Silverstone's 1kw unit ran me just about $300 and its pretty future proof. I expect to have it for 10 plus years.

No it doesn't. A single 8800GTX pulls no where near 200watts. They use more like 150-175watts. The Skulltrail test system with two 8800GTX's pulled only 589watts under full load. That is a system with dual processors and dual video cards. Two hard drives and one optical drive were also used in the configuration.

As for never going past 1kw you are again mistaken. My own system isn't that far off with an overclocked Q6600 and three 8800GTX's, along with two optical drives and four Raptors pulls about 776watts under full load. If I had a lesser power supply I'd probably wear out the damn thing pretty quickly as it would be running near capacity much of the time.

They'll likely change the power connectors on you before then.

Buddy of mine stupidly anal like you, bought a 1200W power supply a few years ago for like $300, had the old 20pin connector. Built a new system recently, bought yet another power supply due to the new 24pin connectors, new pcie power connecters, new sata power connectors, etc. Iolled.

Indeed. The specifications change all the time. ATX 1.0/2.0/EPS12v just to name a few semi-recent standards.

Power supplies only output the amount of power the system draws, they do not output their full capacity at all times.

Right. I don't think that many people understand this.

The combined wattage from all 3 systems in sig is roughly around 600w... Measured at the wall, so approximately 500w from the PSU.

Unless you're running Quad SLI, there's no reason to have over 700w...

Kill-A-Watt?



There are plenty of reasons.

There are indeed plenty of reasons to have more than 700watt PSUs.

 

[WhoBeDaPlaya]

Unless you're running Quad SLI, there's no reason to have over 700w...

Watts don't mean a thing. How much amperage you need does
That said, you don't want to run your PSUs at max load (target about ~55% thereabouts) which is why I have 2x 500W X-Finitys running an OCed E6400 (3.4GHz), 8500GT, single DVD/RW, 10 fans and 15 7200rpm HDDs. Startup load's a bitch

 

[Menelmarar]

Watts don't mean a thing. How much amperage you need does
That said, you don't want to run your PSUs at max load (target about ~55% thereabouts) which is why I have 2x 500W X-Finitys running an OCed E6400 (3.4GHz), 8500GT, single DVD/RW, 10 fans and 15 7200rpm HDDs. Startup load's a bitch

P=EI and E is a known constant at either 5V or 12V for most system components.

 

[skadebo]

Watts don't mean a thing. How much amperage you need does
That said, you don't want to run your PSUs at max load (target about ~55% thereabouts) which is why I have 2x 500W X-Finitys running an OCed E6400 (3.4GHz), 8500GT, single DVD/RW, 10 fans and 15 7200rpm HDDs. Startup load's a bitch

I was going to make fun of you for using dual 500W PSUs until I re-read and saw how many HDs you're running.

 

[Arcygenical]

Kill-A-Watt?

There are plenty of reasons.

Yes, KAW.

What are the reasons? I'd rather have a good quality PSU with low ripple, or get a PCIe SATA card with staggered startup, then spend 300$ on a 1kw psu, when 99.9% of systems use less than 500w.

Remember, I said, "Unless you're running quad SLI" and by this, I mean any extreme application, such as skulltrail, servers, multiple systems from the same PSU.

There are indeed plenty of reasons to have more than 700watt PSUs.

Like? A HX620 can easily run an 8800GTX SLI setup, even with a quad if you can keep it under 50c... and have a single HD.

Watts don't mean a thing. How much amperage you need does
That said, you don't want to run your PSUs at max load (target about ~55% thereabouts) which is why I have 2x 500W X-Finitys running an OCed E6400 (3.4GHz), 8500GT, single DVD/RW, 10 fans and 15 7200rpm HDDs. Startup load's a bitch

Right, but how many 700w psu's do you see with all the amperage on the 3 and 5v lines

Everything is "pump the 12v" these days, so I'm assuming you're buying a reputable brand...

Well, 15 7200rpm drives are "Server" territory which falls under the extreme category I listed above.

 

[lamboman]

Yes, enthusiast (not budget) systems are pulling more power than they used to. But, think about how much faster they are.

As for uber high wattage supplies, they should be more efficient, in theory, than a 600W supply running at nearly full load. Of course, in reality, it doesn't always work like that, and the difference is barely noticable.

 

[Dan_D]

Yes, KAW.

What are the reasons? I'd rather have a good quality PSU with low ripple, or get a PCIe SATA card with staggered startup, then spend 300$ on a 1kw psu, when 99.9% of systems use less than 500w.

Remember, I said, "Unless you're running quad SLI" and by this, I mean any extreme application, such as skulltrail, servers, multiple systems from the same PSU.

Like? A HX620 can easily run an 8800GTX SLI setup, even with a quad if you can keep it under 50c... and have a single HD.

Again I know that an 8800GTX SLI setup can certainly be run on less than 700watts. I never said it couldn't. However configurations that use closer to 700watts of power or more are not that unusual in an enthusiast machine. Especially since most of us have at least two or three hard drives added to the mix.

 

[Sunin]

No it doesn't. A single 8800GTX pulls no where near 200watts. They use more like 150-175watts. The Skulltrail test system with two 8800GTX's pulled only 589watts under full load. That is a system with dual processors and dual video cards. Two hard drives and one optical drive were also used in the configuration.

Each GTX if I recall is rated at something like 185w, and my first comment said a Single GTX system, would pull 250ish watts, and about 400-450 in SLI. Add in other things and you can push 500-550. That is all accurate from everything I've read. So 589 - 65 watt processor = 524? no? That's in my range I quoted.

Maybe I missed something?

 

[Sunin]

Again I know that an 8800GTX SLI setup can certainly be run on less than 700watts. I never said it couldn't. However configurations that use closer to 700watts of power or more are not that unusual in an enthusiast machine. Especially since most of us have at least two or three hard drives added to the mix.

And raptor drives at that, plus sound card, plus a couple of DVD and HD DVD drives and a 3.5, and... hehe you can push the 700 watt mark if everything in the system decides to utilize its max power at once. (rarely done)

I would agree a solid 750w psu should be good for most things.

Now the new 9800GX2 is supposedly rated between 250-270w each. If you SLI those that definitely woudl be taxing a 750w psu.

Thus like I originally said I went 1kw to future proof and just plain never have to worry about my power requriements ever.

Also the Silverstone is rated at 80amps per rail, and the PC&P 1kw is rated at 85amps per rail. Not saying it isn't doable but that would be one helluva power draw!

 

[[Spectre]]

Yes, KAW.

What are the reasons? I'd rather have a good quality PSU with low ripple, or get a PCIe SATA card with staggered startup, then spend 300$ on a 1kw psu, when 99.9% of systems use less than 500w.

Jon and I go through this all the time so one of us really should keep a copy paste response.

Ok here goes again.

1) Build quality. Typically higher end units have better build quality units than lower end units. Higher end units also typically come in higher output capacity.
2) Ripple/Noise generally increases with load. The higher percentage the DC output capacity your are using the greater the ripple/noise values.
3) Efficiency peaks at 40-60% typically so you kind of want to be near that range.
4) Lifespan. The lifespan is increased when running at a lower total percentage of the units output.
5) Temperature derating. Units derate with temperature so you are losing capacity for every degree above the units rated at temperature in to a user an unknown derating curve.
6) Transient loads. You don't actually know what the transient loads look like in a unit and your Kill-A-Watt won't register it as its sampling time is too slow. So you don't actually know the peak draw you are using.
7) Inaccurate maximum draw figure. See picture above.
8) Noise. A unit running at a greater DC output level percentage will in general be louder.

 

[Dan_D]

Each GTX if I recall is rated at something like 185w, and my first comment said a Single GTX system, would pull 250ish watts, and about 400-450 in SLI. Add in other things and you can push 500-550. That is all accurate from everything I've read. So 589 - 65 watt processor = 524? no? That's in my range I quoted.

Maybe I missed something?

I didn't say that your statement was inaccurate. What I said was that systems that do pull more than 500watts aren't uncommon. Usually the systems that do pull that much power are going to be higher end SLI systems with overclocked processors and multiple drives and tons of fans. Or if they are water cooling they could have water pumps in there as well. So agian I wasn't disagreeing with you just stating that there are plenty of systems out there that need PSUs capable of out putting 700 watts or more.

As for the 8800GTX's they don't actually usually require the full amount of power they can draw. Normally I think they run under 150watts each. Truthfully most hardware doesn't pull the max draw their specifications call for. The Skulltrail platforms QX9775 processors have a max TDP of 150watts each. On paper the Skulltrail system should have drawn quite a bit more power than it did in reality. On the processors and video cards alone it should have pulled over 600watts but it never did during testing even when the hard drives, memory, fans and everything else were factored in. So while you can get by with less it is always wise to keep your PSU output at around 50-60% and to also use a PSU that can handle the maximum out put required by your hardware under the worst circumstances. Let's also not forget that PSUs become less efficient as they heat up and as they age. So again I'd take the maximum power out put you need theoretically and add 30% to your PSU rating. Intel recommends no less than a 1kw PSU for use with Skulltrail and they recommend 1200watts to 1600watts depending on how many video cards your are using. While this thread isn't about Skulltrail, the technical data for it is fresh in my mind and I think it makes a good example of what I'm talking about.

Again there are plenty of reasonable scenarios where more than 700watt PSUs are required or are at least desirable.

 

[Arcygenical]

Jon and I go through this all the time so one of us really should keep a copy paste response.

Ok here goes again.

1) Build quality. Typically higher end units have better build quality units than lower end units. Higher end units also typically come in higher output capacity.
2) Ripple/Noise generally increases with load. The higher percentage the DC output capacity your are using the greater the ripple/noise values.
3) Efficiency peaks at 40-60% typically so you kind of want to be near that range.
4) Lifespan. The lifespan is increased when running at a lower total percentage of the units output.
5) Temperature derating. Units derate with temperature so you are losing capacity for every degree above the units rated at temperature in to a user an unknown derating curve.
6) Transient loads. You don't actually know what the transient loads look like in a unit and your Kill-A-Watt won't register it as its sampling time is too slow. So you don't actually know the peak draw you are using.
7) Inaccurate maximum draw figure. See picture above.
8) Noise. A unit running at a greater DC output level percentage will in general be louder.

Nice test setup there!

But I just don't see how recommending a good 700w-1kw unit is better than say, a good 600w unit when you're only going to be using 350w at load, or potentially even less. I'm talking, a good Corsair unit, PCPnC, or a silverstone... Not a "Super sparkle" 600w (although I do know sparkle PSU's aren't as bad as their name would suggest!)

I know Corsair rates their PSU's at 40c, rather than an industry standard 25c-30c and the air leaving my PSU never reaches above 27c.

And the KAW, from what I can tell, is 9w off from your much nicer unit... That's an inaccuracy of 5%.

I just don't see how spending 300$ on a PSU, compared to 120$ is a good Idea... Sure, the expensive PSU might last 5 years longer, but you can just buy another, potentially better PSU for the same price to make up for your first one, if it dies (which it probably won't due to load stresses). I expect 800w PSU's to come down into the range of 600w PSU's in 5 years... With the way computers are progressing.

There are definite exceptions, but I don't think there are LOTS of compelling reasons to shell out for 50% power capacity over what you'll ever use during a cold start, in january with a bit of capacitor wear...

But, then again I'm talking to Dan_D, the master of spending a ton on his computers, and getting every goddamn performance point he can on them, and a couple of PSU enthusiasts/moderators/reviewers... I'm just a watercooling guy that values silence and loves to mod

 

[NKDietrich]

People seem to be confused.

You shouldn't be running a PSU near its max capacity! It shortens the lifespan of the parts, usually increases fan speed and noise, etc.

The point of a 1000+w PSU isn't (usually) to run a system that takes nearly 1000 watts at load, it's to run a system that takes 500-800 watts at load so that you're in the efficiency sweetspot of the PSU.

 

[WhoBeDaPlaya]

What are the reasons? I'd rather have a good quality PSU with low ripple, or get a PCIe SATA card with staggered startup, then spend 300$ on a 1kw psu, when 99.9% of systems use less than 500w.

Can't beat the 8-port SuperMicro SAT-MV2 for $49

 

[Arcygenical]

The point of a 1000+w PSU isn't (usually) to run a system that takes nearly 1000 watts at load, it's to run a system that takes 500-800 watts at load so that you're in the efficiency sweetspot of the PSU.

Which would be an 8800 GTX SLI system with a Q6600 and raptors in Raid0... Easily run from a 700w unit unless you'll be overclocking like a BAMF.

 

[Dan_D]

But, then again I'm talking to Dan_D, the master of spending a ton on his computers, and getting every goddamn performance point he can on them, and a couple of PSU enthusiasts/moderators/reviewers... I'm just a watercooling guy that values silence and loves to mod

I resemble that remark.

 

[Arcygenical]

I resemble that remark.

I know you do. And never forget, I'm jealous of your position here, and ability to feed your hobby .

 

[jonnyGURU]

Nice test setup there!

But I just don't see how recommending a good 700w-1kw unit is better than say, a good 600w unit when you're only going to be using 350w at load, or potentially even less.

I think that's a big point right there. I know you're not assuming everyone is only using 350W, but if you have dual graphics cards or dual processors or a bunch of drives, you're going to need more power. Typically 550W or more.

Add to that all of the points Paul pointed out: It's NOT good for a PSU to be running at 75%+ capacity all of the time, the PSU is NOT going to be running at it's coolest. The PSU fan is NOT going to be running at it's slowest. Ripple and noise is NOT going to be at it's lowest, etc. and you have a good reason to get an 800W PSU when you "really only need 500W."

Mind you, I agree that a GOOD 600W is going to be satisfactory for 99% of the people out there with a more than adequate safety buffer. I'm not going to argue that.

BTW: A Quad FX system with a pair of 8800 Ultra's and only two hard drives in RAID won't even boot into Windows with anything less than a good 700W PSU. Make that SLI and it won't even post with an 800W PSU. Even a Quad Core with three way SLI chokes with a 700W, but that's talking about the exception... not the norm.

 

[Arcygenical]

SNIP

I totally agree with everything you said. In fact, I know a Quadfather or a skulltrail requires probably a kilowatt to get going smoothly, and would like to see it run on a 230w for kicks.

And I guess this is just a discussion of semantics, rather than technology then... I was only ever in disagreement for there being "lots" of reasons to require this ability to supply loads of power. Certain situations, I totally understand, but these are probably far and few between.

That's just my opinion... I think there's one or two very limited situations where this is required, and those being dual socket, or triple GPU, which is less than a tenth of a percentage of consumer marketshare these days IMO.

And, I'm also on the defensive about this too. Too many goddamned manufacturers are pushing these power supplies with arguable quality, and ridiculous specifications, and forcing it into user's heads that you need a kilowatt to run a quad + single GTX system. And that really irks me the wrong way, just as the gigahurtz arms race did.

 

[Sunin]

Jon and I go through this all the time so one of us really should keep a copy paste response.

Ok here goes again.

1) Build quality. Typically higher end units have better build quality units than lower end units. Higher end units also typically come in higher output capacity.
2) Ripple/Noise generally increases with load. The higher percentage the DC output capacity your are using the greater the ripple/noise values.
3) Efficiency peaks at 40-60% typically so you kind of want to be near that range.
4) Lifespan. The lifespan is increased when running at a lower total percentage of the units output.
5) Temperature derating. Units derate with temperature so you are losing capacity for every degree above the units rated at temperature in to a user an unknown derating curve.
6) Transient loads. You don't actually know what the transient loads look like in a unit and your Kill-A-Watt won't register it as its sampling time is too slow. So you don't actually know the peak draw you are using.
7) Inaccurate maximum draw figure. See picture above.
8) Noise. A unit running at a greater DC output level percentage will in general be louder.

I can't agree more here! 350w system = 700 w psu.. to fall in line with #3. I think you will be fine with a $100-150 700 to 750w psu in most cases, if you water cool and are a bit more extreme then you go for the 1kw. I water cool my system so I'm running everything and a water pump, 3 radiator fans, 2 case fans, Memory fans, plus SLI 8800GTX's etc. It adds up and honestly I have no worries with the choice I picked. Plus I push my OC's I've had my processor up to nearly 4ghz, if the mobo would not limit me I think I would have broken that mark.

 

[Dan_D]

I totally agree with everything you said. In fact, I know a Quadfather or a skulltrail requires probably a kilowatt to get going smoothly, and would like to see it run on a 230w for kicks.

And I guess this is just a discussion of semantics, rather than technology then... I was only ever in disagreement for there being "lots" of reasons to require this ability to supply loads of power. Certain situations, I totally understand, but these are probably far and few between.

That's just my opinion... I think there's one or two very limited situations where this is required, and those being dual socket, or triple GPU, which is less than a tenth of a percentage of consumer marketshare these days IMO.

And, I'm also on the defensive about this too. Too many goddamned manufacturers are pushing these power supplies with arguable quality, and ridiculous specifications, and forcing it into user's heads that you need a kilowatt to run a quad + single GTX system. And that really irks me the wrong way, just as the gigahurtz arms race did.

In the documentation I have, Intel only recommends one PSU for Skulltrail and that's the Thermaltake Toughpower 1200watt. They mention needing a 1600watt PSU for quad GPU configurations.

 

[NKDietrich]

In the documentation I have, Intel only recommends one PSU for Skulltrail and that's the Thermaltake Toughpower 1200watt. They mention needing a 1600watt PSU for quad GPU configurations.

1600watt... that's rather scary. Since there is one PSU that can do it.. and it requires its own 20amp circuit with a 5-20R outlet to do so.

That being said... yesterday I finished putting my system on its own 20amp circuit just in case it comes to that eventually...

 

[ND40oz]

In the documentation I have, Intel only recommends one PSU for Skulltrail and that's the Thermaltake Toughpower 1200watt. They mention needing a 1600watt PSU for quad GPU configurations.

Jeez, I hope my ST1000 can handle two 5355s and two 2900XTs then...guess I'll find out when the DSEB-DG finally arrives.

 

[Dan_D]

Jeez, I hope my ST1000 can handle two 5355s and two 2900XTs then...guess I'll find out when the DSEB-DG finally arrives.

It will. With dual 8800GTX's the Skulltrail (complete with QX9775's) only pulls 589watts under full load.

 

[[Spectre]]

And the KAW, from what I can tell, is 9w off from your much nicer unit... That's an inaccuracy of 5%.

No the Kill-A-Watt is showing an AC draw of 9w BELOW the DC draw (that is a SM-880 showing DC draw)on a unit that is actually ~77% efficient at that load. That is far more than a 5% error which would still be completely unacceptable.

Don't trust a Kill-A-Watt top give you anything resembling the correct value if you have a PSU with APFC that you can't verify the APFC circuitry does not interfere with the Kill-A-Watt.

 

[Mithent]

No the Kill-A-Watt is showing an AC draw of 9w BELOW the DC draw (that is a SM-880 showing DC draw)on a unit that is actually ~77% efficient at that load. That is far more than a 5% error which would still be completely unacceptable.

Don't trust a Kill-A-Watt top give you anything resembling the correct value if you have a PSU with APFC that you can't verify the APFC circuitry does not interfere with the Kill-A-Watt.

From the PSU test methodology: "Efficiency is calculated by the input wattage read at the Kill-A-Watt divided by the output wattage of the PSU and is recorded across all of our tests"

If the Kill-A-Watt is so inaccurate that it can show the AC draw below the DC draw, how is it that you get sensible values for PSU efficiencies? Many PSUs have APFC now.

 

[jonnyGURU]

And, I'm also on the defensive about this too. Too many goddamned manufacturers are pushing these power supplies with arguable quality, and ridiculous specifications, and forcing it into user's heads that you need a kilowatt to run a quad + single GTX system. And that really irks me the wrong way, just as the gigahurtz arms race did.

It's fine to be on the defense about dubious power supplies that actually need for the user to buy three to four times what they need because the PSU in question can't even do half of what it's labeled to do. But don't suck in power supplies that can actually DO what they're supposed to do in with that crowd.

The platform used for the Thermaltake Toughpower 1000W, 1200W and 1500W is a unique CWT platform limited to those 1000W and up platforms. You can't get the superb construction, regulation, etc. in any model Toughpower < 1000W. If the 1000W is in my budget, even if I only "need" 500W, why should someone be allowed to tell me not to buy it because it's "too much power"? Nobody "needs" a Lexus or Infiniti or Mercedes, and if we applied the same rule we'd all be driving Hyundai Elantras.

The platform that I'm using for BFG's new PSU comes in only 800W. Why? Why not 600W? 700W? Because at the cost of the components required to build a PSU at this level, it simply would not be financially feasible to make it in a 600W version. If I was trying to sell an 800W at $229 and a 600W at $219, both units with the same quality, performance, etc. I would be laughed at because $219 is way too much money for a 600W PSU and the average customer would not hesitate investing an additional $10 to get something capable of putting out 200W more.

But back to the PSU's that say they're 750W and can only put out 500W... that's a whole other story. That's not a matter of people buying PSU's that are far more capable than what they need. That's a matter of companies selling crap at a premium knowing that most people are unable to discover that their PSU really can't do everything the box says it can do. IMHO, a totally separate issue.

 

[jonnyGURU]

If the Kill-A-Watt is so inaccurate that it can show the AC draw below the DC draw, how is it that you get sensible values for PSU efficiencies? Many PSUs have APFC now.

He probably should update the methodology. See the green box to the left of the picture? That's a Brand measurement device and that one is a bit more accurate.

 

[[Spectre]]

From the PSU test methodology: "Efficiency is calculated by the input wattage read at the Kill-A-Watt divided by the output wattage of the PSU and is recorded across all of our tests"

If the Kill-A-Watt is so inaccurate that it can show the AC draw below the DC draw, how is it that you get sensible values for PSU efficiencies? Many PSUs have APFC now.

He probably should update the methodology. See the green box to the left of the picture? That's a Brand measurement device and that one is a bit more accurate.

Yeah what jonnyGURU said. I ditched the Kill-A-Watt for most units after I lost two of them during the 450w-500w roundup to PowerTek unit that blew out on the AC side. Now I use primarily the special order Brand with current transducer and another Extech unit depending on the power supply.

As for the APFC it isn't all APFC units its just some that have a specific APFC 12v rectification methodology, though they do seem to be growing in number.