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Discussion Power supply discussion and recommended models thread

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USAFRet

Titan
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Mar 16, 2013
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I'm guilty.

Of calling psus junk, and some truly are. But generally that's not entirely truthful. It'd be far more accurate to call those 'junky' claimed psus as terrible, for gaming or production usage, instead. There's realistically nothing wrong with the VS, B1, NEX, even the old green label CX, IF they are used for what they are realistically intended for, Grandma's websurfer. It's only the higher end, enthusiast class, pro editor, content creator type builds running high end gpus, massive cpus that need the appropriate psu, both in wattage and quality.

But for an everyday websurfer, with a tiny gpu, igpu that'd be lucky to see over 200w if pushed.. Those junky units work just fine and generally last for years.

Of course that's not including the real junk, the no-name, off brand, light as a feather garbage put out by vendors such as Circle, insignia, compucase, and anything with a brand name written in Chinese characters with English subtitles.
Or, after 4 years of use and then sitting on the shelf for 6 months, a green label CX600 ate one of my motherboards on first power up.
 

Karadjgne

Titan
Herald
Sorry to hear about the motherboard, but you did get 4 years out of that green label CX, which is quite a decent amount of time since they averaged 18 months or so. It survived long enough to retire its warranty period, which is an accomplishment in itself.

But that beggars the question, just why would you put it on the shelf in the first place? At 4 years, retirement means doorstop, coaster, spare parts, paperweight, anything but a return to active duty.
 

USAFRet

Titan
Moderator
Mar 16, 2013
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Sorry to hear about the motherboard, but you did get 4 years out of that green label CX, which is quite a decent amount of time since they averaged 18 months or so. It survived long enough to retire its warranty period, which is an accomplishment in itself.

But that beggars the question, just why would you put it on the shelf in the first place? At 4 years, retirement means doorstop, coaster, spare parts, paperweight, anything but a return to active duty.
It was on the shelf due to multiple systems being rebuilt and parts swapped around.
I didn't need it, so it went on the shelf.
Later, building up a low power HTPC, I had it, so thought to use it.

Poof, dead motherboard.

Your statement of "averaged 18 months" goes against your earlier "Those junky units work just fine and generally last for years. "

In any case...not to be recommended.
 

Darkbreeze

Titan
Moderator
If a PSU is rated for 450w, it ought to be able to sustain 450w with a gaming load.

If the PSU cannot do that, there is a problem.
This, is EXACTLY right. If a PSU "SAYS" it is 450w, then 450w is what it NEEDS to be ABLE to suport. Continuously, at 40°C AT LEAST. 50°C would be better. Regardless of WHAT is it used for or what kind of hardware it has, so long as the draw isn't more than 450w then any 450w unit can either provide that reliably for at least as long as the warranty period, or it's a piece of junk. Period.

AND, if the warranty is less than three years, then IMO, it's automatically a piece of junk right off the bat. No PSU with less than a three year warranty should ever be recommended, trusted or purchased, by anybody, for anything, regardless of claims of fitness for a particular use.
 

Karadjgne

Titan
Herald
@USAFRet

Not really 'goes against', that average includes all those using those CX 550, CX 600 on the old R9 series like 280/280x/290's etc, where 6 months or less was the average lifespan. But there were multi postings of ppl getting 4 years+, on 750ti builds etc. But that was back when 3 years was a decent average warranty for most all the more budget psus, Seasonic included. I just tossed an old CoolerMaster 600 that went through 3 pc's and about 6 years of usage, but never saw anything more than a P4 and 8800 GT/ x800. 300w if it was lucky.
 
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If a PSU is rated for 450w, it ought to be able to sustain 450w with a gaming load.

If the PSU cannot do that, there is a problem.
And should be able to run with hardware that consumes less power than the rated wattage while not having its protections kick in.
 
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even the old green label CX,
Not all greenlabels. 750w+ have the same internals as Cxm greylabem.

It's only the higher end, enthusiast class, pro editor, content creator type builds running high end gpus, massive cpus that need the appropriate psu, both in wattage and quality.
Unless you are running HEDT hardware or multiGPUs you rarely if ever need to exceed a good 550w.

And if you are gonna exceed 750, you should aim for multirail units.
 
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4745454b

Titan
Moderator
And if you are gonna exceed 750, you should aim for multirail units.
And why is that? I know of only one reason to use a multi rail unit, and that doesn't happen until around 1500W.

As for the green label, you went well past it's warranty. I don't remember if they were warrantied for 2 or 3 years, but you got four out of it. I would have stopped using it then. Before the fire I was starting to look at new PSUs because my Leadex based PSU was at the end of its warranty. Anything longer and you are playing with fire. Possibly literally.
 
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And why is that? I know of only one reason to use a multi rail unit, and that doesn't happen until around 1500W.

reaction time/sensetivity during certain load scenarios to protect the PSU and the system its powering. and when you need more than a 750w PSU, you are within the reach of such scenarios.

As for the green label, you went well past it's warranty. I don't remember if they were warrantied for 2 or 3 years, but you got four out of it. I would have stopped using it then. Before the fire I was starting to look at new PSUs because my Leadex based PSU was at the end of its warranty. Anything longer and you are playing with fire. Possibly literally.
that is very paranoid to stopp using a PSU when its warranty ends....... as if a PSU has lasted that long, its likely to last for a long long time.

edit: also fires afaik only really happen in dissasterunits
edit2: if one is gonna be that paranoid regarding warranty, id especially be on the more conservative side regarding high wattage single-rail PSUs
 
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Darkbreeze

Titan
Moderator
It is not paranoid, it is preemptive, and it's not a bad thing. For the comparatively cheap cost of a decent new power supply compared to the replacement of a good motherboard, CPU or graphics card, or a large drive, it makes a lot of sense to replace a power supply that has reached it's warranty age if you still value the hardware it is powering by that point and then potentially move that still working PSU into a system that is either low value and not a big concern OR shelf it for a backup in the even that your replacement unit must be RMA'd. Not everybody's unit, after being shelved, blows up their motherboard. Although that's certainly a possibility and you might alternatively wish to simply throw it away.

I don't recommend continuing to use power supplies with hardware you care about much beyond the warranty UNLESS it is a unit that the manufacturer actually offered extended warranty coverage for beyond it's standard warranty. They don't usually do that unless they believe the platform and component selection is good enough to warrant it.
 

TJ Hooker

Glorious
Herald
that is very paranoid to stopp using a PSU when its warranty ends....... as if a PSU has lasted that long, its likely to last for a long long time.
What are you basing this on? I would assume that PSUs follow the typical 'bathtub' curve for failures. It is in the manufacturer's best interest to set the warranty somewhere just before the knee point of the curve, i.e. where failure rate accelerates.

For instance, electrolytic caps are rated for a finite lifespan in operating hours.
 
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For instance, electrolytic caps are rated for a finite lifespan in operating hours.
they are rated at a certain lifespan at a given temperature. usually a fairly high temperature you dont see in regular PSUs. meaning they will last longer than their rated lifecycle. could be a culprit for the warranty, but i doubt it.

What are you basing this on? I would assume that PSUs follow the typical 'bathtub' curve for failures. It is in the manufacturer's best interest to set the warranty somewhere just before the knee point of the curve, i.e. where failure rate accelerates.
if there was an issue with the PSU it would most likely have issues in the beginning or when it reaches a certain load scenario.

the issue with it following i failure rate curve is that the warranty is put there since day 1. its most likely a extent of time that given manufacturer want to give warranty for.

They don't usually do that unless they believe the platform and component selection is good enough to warrant it.
from what ive noticed, a lot of companies dont do extended warranty regardless of how good the plattform may be. and warranty really isnt the expected lifespan of a unit, its more how much money a company is willing to spend on maintaining a warranty service. and longer warranty is something you can do with a higher margin product.
 

Darkbreeze

Titan
Moderator
It is ALSO something you would NOT do with a product you know you are going to have to watch come back in your door after a certain period of time, so again, using it beyond the warranty is poorly advised if you value the hardware. Sure, I have seen plenty of power supplies last years beyond the warranty. I've also seen plenty of them either not make it to the warranty's conclusion or die/start having problems not long after. Manufacturers know "about" how long the hardware is going to last based on testing and selected component expectations. If a company REALLY believes a unit will last 7-8 years, then they will set the warranty to 7 years, not 5. It is a selling point. If they think the unit can last ten, they are not going to set it to 7 when a competitor has a similarly priced unit with a 10 year warranty.

I have a feeling we've met you before, by a different name.
 
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TJ Hooker

Glorious
Herald
they are rated at a certain lifespan at a given temperature. usually a fairly high temperature you dont see in regular PSUs. meaning they will last longer than their rated lifecycle. could be a culprit for the warranty, but i doubt it.
When I referred to lifespan I was meant the rated lifespan after it had been appropriately derated (or whatever is the opposite of derating I guess) based on expected operating temps.

if there was an issue with the PSU it would most likely have issues in the beginning or when it reaches a certain load scenario.

the issue with it following i failure rate curve is that the warranty is put there since day 1. its most likely a extent of time that given manufacturer want to give warranty for.
Are you suggesting that manufacturers just pick a number for warranty with no idea how long the PSUs will actually last in practice? I would assume they do some sort of accelerated life testing, and/or take failure data from previous comparable units (or use industry resources for failure rates for different components), to come up with an estimate for how long a new unit can be expected to last.
 
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In my opinion using an out of warranty isn't really an issue in many cases.

If you are bareily loading a quality PSU for many years, it should be fine out of warranty as it has not been "worn out".

As they do age i wouldn't load an old PSU with high end hardware tho.
 

Darkbreeze

Titan
Moderator
Obviously, we are conversing about the use of systems with heavy demands. If somebody is using a five year warranty unit that is seven years old and has a 550w capacity, but is only running a basic system using integrated graphics or a slot powered graphics card, then it's probably not a major concern. Even so, once you leave the warranty period the chances that SOMETHING is going to go wrong with the unit jumps exponentially so it STILL might be a good idea to replace it. Capacitors really don't care that you are using only 250w out of the 550w it was designed to accommodate. They really only know that they are old and weepy.
 
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It is a selling point
its also a cost, a cost you wouldnt put on lower margin products. can you afford to put a 7 year warranty on the 80$ PSU? you might not be able. so you drop the warranty period. under no fault of the PSU.

If they think the unit can last ten, they are not going to set it to 7 when a competitor has a similarly priced unit with a 10 year warranty.
they might do so if it gives them slightly more profit margin.

Are you suggesting that manufacturers just pick a number for warranty with no idea how long the PSUs will actually last in practice?
they might do so, but i more expect them to pick a number they can appropriatly give within their margins. they probably has some groundwork based on components lifespan and failure rates from manufacture.

As they do age i wouldn't load an old PSU with high end hardware tho.
just so you know, degredation of PSUs was debunked years ago. when it comes to ATX spec requirements of newer hardware, thats a different matter.

Im pretty sure i know who you are talking about
I have a feeling we've met you before, by a different name
id love to hear who, because im fairly certain im not the person you think i am.
 
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Capacitors really don't care that you are using only 250w out of the 550w it was designed to accommodate. They really only know that they are old and weepy.
are you arguing capacitor degredation? because that was also debunked years ago. there is a liferating at a certain temperature sure, but thats at a temp a PSU usually doesnt run at.

Even so, once you leave the warranty period the chances that SOMETHING is going to go wrong with the unit jumps exponentially so it STILL might be a good idea to replace it.
if you like being under the blanket of a warranty, its not a terrible idea of replacing it. people do like comfort of not thinking about the PSU. not that a lot of people do, but there is allways some.

is it a major driving factor of swapping a PSU? not really.
 
just so you know, degredation of PSUs was debunked years ago. when it comes to ATX spec requirements of newer hardware, thats a different matter.
Source?

Capacitors do not age well. I have seen capacitors bulge and leak with age, especially in PC/monitor power supplies or even motherboard vrms. Solid capacitors help, but still wear.

Heck, capacitor leakage over time is a real problem. There were some apple computers back in the 80s which could have the motherboards completely eaten away by leaking caps.

PSU fans fail commonly. Especially low end sleeve or rifle bearing fans.

PSUs build with dust and can run hot after years.
 
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PSU fans fail commonly. Especially low end sleeve or rifle bearing fans
its why OTP is more important that some people claim it is.

PSUs build with dust and can run hot after years.
even better reason why OTP is so important. but it also runs under the assumption that the PSU runs in a borderline state of shutdown for shorter than expected overtime of the rated lifespan of a cap.

i believe i got that claim from JonnyGuru, and/or other member of the PSU tierlist at LTT Forum.

Capacitors do not age well. I have seen capacitors bulge and leak with age, especially in PC/monitor power supplies or even motherboard vrms. Solid capacitors help, but still wear.
¨bloatet caps usually come from wrong input voltage if ive understood correctly. and that voltage would come from the PSU. such voltage issues either from Group reg (without UVP or OVP) or otherwise is from what ive understood one of the most common reason why caps bloat and die.

and unless you electrical grid is actually horrid, it doesnt really apply to PSUs as much as it applies to motherboards and GPUs.
 

TJ Hooker

Glorious
Herald
are you arguing capacitor degredation? because that was also debunked years ago. there is a liferating at a certain temperature sure, but thats at a temp a PSU usually doesnt run at.
Ok, now I'm starting to think you're just a troll. Here's an electrolytic cap data sheet, take a look at the Endurance section under Specifications.
https://www.mouser.com/datasheet/2/315/ABA0000C1181-947564.pdf
If capacitor degradation wasn't a thing, why is the tolerance for capacitance greater after 2000 hours of operation greater compared to initial tolerance? Why is tan delta (dissipation factor) allowed to increase by up to double compared to initial value?
 
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