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Five Power Supplies Compared
EconolineCrush writes "Tech Report has done up a comparison of five high-end power supplies that looks at actual voltage levels and AC ripple content. The article also takes a look at environmental factors like noise levels and each power supply's impact on system temperatures. Think power supplies with like wattages are created equal? Think again."
For best results, use a good brand's PSU. Not the latest "XXX Watt" from No-NameBrand
Incidentally, you get what you pay for.
Now I'll go RTFA and see if I'm right, but I've got a _feeling_ about this one.
I assert that my comment is only my opinion, not that of any employer, past, present or future.
Is there something that these power supplies contribute towards overall system stability that "cheap" ones don't? Are they really worth the money?
The article was very good at measuring everything measurable about the power supplies, but didn't answer the question "Why would I want one of these?". So why would I?
My other car is first.
I seriously tire of "tech" reviews on stuff like power supplies, roll out keyboard drawers, cd holders, etc... This is the third "tech" article about power supplies I've seen here in a year.
Here's all you need to know:
Pick up two of the same rating, different brands. The heavier one is better - more windings on the coils and better components.
The end.
I don't need no instructions to know how to rock!!!!
http://www.tomshardware.com/howto/20021021/index.h tml
:)
21 power supply tested here
While this may be true I have never once been able to attribute any PC problems to the power supply. In fact the only time I have changed them was when power requirements increased or when the cooling fan started squeaking and causing the PS itself to over-heat. Not sure they are actually worth the money unless you into things like specmanship and my X is bigger, faster, cooler, etc.. than your X.
TT
in my experience quiet power supplies are quiet because they have slower fans, and so result in a hotter case. So you end up putting in faster & noisier case fans, and get back where you started.
Before I read the article my guess was that Antec would win...and I was right. From the low end to the high end these guys have got their stuff together.
Most of the cases we buy come with Enlight power supplies (they are Enlight cases after all for the most part). Although these Enlight PSes seem to be ok, I always replace them with a nice quiet reliable Antec when they are going home to me or to my family. I also recommend putting an Antec PS in to customers who buy the biggest, baddest gaming PCs.
The simple fact of the matter is though, that most folks don't really need a 550 watt PS. A 350 watt PS will more than handle the load of most average consumer PCs. I do dread opening up an e-Machine or various other "value" (aka cheap ass P.O.S) PC and seeing a 130 watt PS running a P4 CPU. *shudder*
Duris MUD - The best pkill MUD. Ever.
As an addon to that question...
Is it worth buying two cheap-o power supplies that cost less combined than an expensive one so you have a spare?
While all of these look good and they all have some pretty spiffy specs, it would have been nice to have seen some reliability test scores in there. A flaky power supply is a hard thing to track sometimes, and knowing which ones have the best chance of running reliably for the longest time period would be handy information, especially for those of us who have fought with bad power supplies at one point or another in the past.
Be excellent to each other. And... PARTY ON, DUDES!
Good PSUs contribute a lot towards system stability. For example, a moving head in the HDD causes current transients (so does a CPU switching between normal operation and power saving mode). Bad PSUs have huge voltage drops during these transients, good PSUs can buffer them quite well. These transients can cause anything between nothing and total system crash.
Also, the ability to filter noise out of the AC helps with stability...
"Aesthetically, there's not much to see with the SilentX; it looks like, well, a power supply."
Is there something that these power supplies contribute towards overall system stability that "cheap" ones don't?
No, but they'll probably last longer. Your motherboard has a jillion capacitors and whatnot to completely smooth out the power before it hits any chips. Drives are less fussy.
The article was very good at measuring everything measurable about the power supplies, but didn't answer the question "Why would I want one of these?". So why would I?
Because you're one of the brand of "computer experts" who spends as much as he can, puts as many blinking lights and windows as possible into his case. You bought UV-reactive rounded cables to "increase performance". You spent $400 on a watercooling setup to get a 10% FSB speed increase - and are completely ignorant of the fact that you more likely degraded your machines overall performance as a result.
If this is you, you NEED one of these. Two of em, actually. You need ultra smooth high-end power for your peltier plates and water pump, after all.
I don't need no instructions to know how to rock!!!!
I've had so many powersupplies dying on me that it's not even funny. What I want is a PSU that delivers the promised effect, for at least three years. That would be the day.
Might be hard to benchmark that, so anybody got any tips for brands?
How small a thought it takes to fill a whole life
AnandTech also just had a PSU roundup here. The watt numbers and some of that aren't the best from AnandTech's review (read some criticism of it here), but overal it's a good roundup, especially comparing heat and noise.
Power Supply Roundup Part 2
As the article concludes, Antec is the best option available. I run a server with a 300 watt Antec powering the system, and a separate Antec 400 watt running ten of the eleven hard drives. The voltages stay tight and the supplies stay cool. The 500+ watt models are expensive, but the $69 I paid for the 400 watt is well worth it when you are protecting 1.1TB worth of drives.
:(
On the cheap/lower power side, I've had great success with Sparkle and Enlight (250-350 watt) supplies. Priced in the $22-$40 range, these are great for "normal" systems.
I definitely recommend you stay away from the cheap stuff that comes in $30 cases, though... you'll see why when the supply dies, or shorts taking the mobo with it.
I can already imagine a large group of pseudo-overclockcers and case-modders with their pants around their ankles enjoying a nice moment of "stroking the tuna" at the idea of buying a gold-plated, peltier-cooled PSU from a ridiculously expensive brand. Add some bright blue leds and the whole ensemble would fit nicely into ye olde standard Alienware case with prefab case window, prefab neon lights and prefab coloured fans.
So, why do we have an article about expensive PSUs? This is Slashdots "News for Nerds", not "News for 14 year olds who go to LANs with the latest Alienware case daddy bought for them while on parole". Geez. What's next? Comparison of 5 different blue LEDs? "I have concluded that the Antec blue LEDs are definitely more blue then the cheaper LEDs!"
Hate me!
Read this page from AnandTech's PSU roundup. The only thing that was changed between tests was PSUs, yet over a 6 hour time there was a range of only 1 up to 7 memory errors. Just one possible indication of how clean the supply is. Also there's the added benefit that it probably won't die in a month or two (happened to me, not too pleased when it did)
Where can I find this cheap gas now?
Slashdotter are stupid and biased.
I wasn't able to read the article, but there was something I wanted to say about power supplies. It is my understanding that switching power supplies (the kind that are used in pc's) often become more efficient when used close to their maximum rating. Often time people suggest to get a wattage rating a lot higher than you need so you can expand later; but maybe it is better to get a power supply matched to the wattage that you are using -- you could probably at least save on your energy bill that way. Also it may be ok to get a cheap power supply even if it has more AC ripple than more expensive ones because if there is a sensitive circuit on the mother board that needs clean power they always have a nice voltage regulator and cap to clean off the power. Of course you don't want spikes but that is why power surge protectors were invented. Sorry if that was all in the article but like I said it is slashdotted already.
anandtech reviewed 18 units on july 31.
Interesting there is the memory test: they show that stable power gives less memory errors with memtest.
And here is clickable tomshardware:
Toms burns up some power supplies
In a cheap power supply, you can get inconsistent voltages, crazy transients, crosstalk, and if the power demand from one line goes up it can drop the wattage/voltage on the other lines. Cheap power supplies are also frequently noisier (sound too) than high end ones and run less efficiently (read: hot) than better designed, more expensive power supplies. Think about it: your computer operates because of well controlled voltages. If your voltage drops by 2V, some transistors will go into their linear range and cause crazy crazy crap to happen.
http://www.bangedup.com/Current/Openferbusinessfru it.jpg
BUMP IN THE NAME OF GOATSEX BEING A FILTHY ASS!
For the AC ripple measurements it would have been better to put the scope in infinite persistance. Measuring the output over time doesn't really matter. Digital scopes spend the majority of their time sitting around, not measuring signals. So we are missing tons and tons acquistions between each acq.
If he put the scope in infinite persistance we would have seen the ripple voltages grow over time. It would have provided a chance to see an overall (or even average) difference between idle and load.
has a great review of like 15 power supplies. They test actually wattage on all the different channels along with how much memory corruption occurs in a 6 hour period and other stats. Its a great read if you are interesting in high end PS's.
It is strange that there are hardly any truly silent powersupplies, when there is almost no laptop with a powersupply that makes noise..
If powersupply manufacturers simply take out the heat generating part so that you can have it well ventilated and only let the dc wires go into the case, then the completely silent pc would be so much closer.
CC
See my reply here.
The reason they check the voltages so closely is that one you start falling out of the 5 or maybe 10% tolerance zone for many components, over-voltage will cause overheating, lockups and early failure, and undervoltage also frequently causes lockups and occaisionally failure.
Also, some supplies give you a total wattage without breaking down where those watts can go. When you're dealing with processors that pull 80 watts at peak, you REALLY don't want a cheap supply that is busy sending all available watts to 5 and 12 volt channels to power drives.
Another thing to consider when buying a case.. the PS they put in cases are the CHEAP kind, unless they specify what kind it is, I generally expect to replace it within a year. A few years ago I had one of the dual socket370 BP-6 boards, it refused to boot on the PS I had that came with my case (Enlight none the less). I swapped it to a sparkle 300watt and have had no probs since.
This was also recently covered by Tom's Hardware, and earlier by a few other sites. The sparkle and HEC normally blow away the rest, with their 250w beating the specs for most 300+w, and even being able to hold 300w operation themselves.
just my $.02
Tm
Support TBI Research: http://www.raisinhope.org
If you've got weak voltages on the PSU rails, it can kill your HDDs. Some people lose drive after drive and never consider that their voltages are out of spec. Also, if your cheap PSU shorts on the DC side, say goodbye to your drives and maybe your motherboard and everything plugged into it.
"Turn on StickyKeys."
Or use the open source solution, pr0n.
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you get what you pay for.
-Reid
You've got to be trolling. On the off chance that you aren't:
/. intro noted case noise and heat output into the case.
The article started right off by saying that system stability can be affect, that the stability of voltage levels and the amount of electrical noise varies greatly. It also noted that the power supplies distribute their power differently among the various output voltages The
The effects on the CPU, chipset and RAM of electrical noise and/or 'brownouts' of voltage dropping below specs should be obvious. I've seen several systems go instable because the 5vsb line, or some voltage branch like the USB line couldn't drive the attached components. What good is having 200 extra watts you don't need at one voltage, if the PS goes flaky at full output and real usage on another? A lot of power supplies that do fine (or almost fine) on a bench or at 50% of their rated current draw in the real world will flake out occassionally at 85%. A few milliseconds of flaking out ever several hours can turn a dream machine into a nightmare.
Hook an oscilloscope to distal power traces on the motherboard (not near the power supply, and depending on your supply, you can see some pretty ugly stuff as peripherals/cards switch on/off. Sure, a good motherboard should have plenty of well placed filter caps, but on a fully loaded system, you can *see* how adequate they sometimes aren't, if the power supply doesn't supply great power in he first place. It's possible to design very rugged and tolerant motherboards (e.g. military), but in the consumer market, price competition is so tight that boards are often revised in mid-production to save one or two caps.
I'm not saying top-of-the line is always best, but bottom of the line is pretty much asking for trouble down the line. Most people 'add and test' when they build (or expand a system with use), but the culprit may not be the card you just added; it could be the power supply you 'vetted' up front.
Why is it that every time these "high-end" power supplies get compared, the most high-end one always gets ignored? PC Power and Cooling has long manufactured the world's best power supplies. They're the Ferrari or the Moto Guzzi of the power supply world. Yeah, lots of Asian manufacturing firms make OK power supplies, but PCP&C's stuff is the only company that makes boards that the major motherboard manufacturers highly recommend and use exclusively in their own tests. Why does such an obvious high-quality product always get ignored?
Who's their target audience, Fred Sanford???
Rail wattage is also important because power supplies have 12, 5, and 3.3 volt supply rails. If the 5 and 3.3 are sharing the same rail then you are limited to the wattage from that single rail. Antec was the only power supply to have separate 5 and 3.3 rails. If you don't have enough power going to your components under a heavy load, your system will crash. Think of the power supply like a carburetor. If it's running too lean or you put one 2 barrel carb on a Hemi, it won't run right. If your power supply can't get enough voltage or current out to your components, or you put one on that's too small, your computer won't run right.
Needless to say, I'd buy the Antec. Separate rails for 5 and 3.3 plus the second-lowest ripple make it a good choice for stable power.
I paid the price for using a cheap PSU.
The damned thing blew up (went bang, magic smoke came out). When I fitted a new PSU, I found that when it went, it had taken out the motherboard, graphics card, both hard drives and CD-RW drive. The only survivors were the network card, DVD-ROM, keyboard and mouse. The fuse in the PSU didn't even blow.
Meanwhile, the adjacent Sun Ultra 5, Dell PC, printer and other kit carried on running as it always has - so I doubt it was a surge in the mains power.
Oolite: Elite-like game. For Mac, Linux and Windows
I spent two years making an almost silent pc. I picked out low speed fans, the best heatsink, giant passive video card coolers, Lian-Li aluminum case, a baybus to toggle extra fans on and off for hot summer days and gaming, rounded cables, etc.. I had it perfect.
And then my silent power supply up and died. Needing a new one, I went to a local cmoputer shop and bought an Antec Truepower, which was advertised as silent. Man was I wrong. It regulates its temperature, so the hotter it is inside the case the faster the fan spins, and it always seems to want to spin at top speed, despite the fact that my cpu isn't going to die a fiery death at 45c anytime soon. The incessant grinding drives me insane.
If it didn't take 4 hours to take the psu out of my setup and then another 4 to put in a costly new one, I'd be happy.
After several failing power supplies, earlier this year I decided to get a good power supply. I read their review (and assorted other reviews) last year and bought the TruePower 550.
It is pretty quiet and has run great and it is nice to see it running so well against the newer models.
I won't buy another cheap power supply again.
From the article:
Would you dare put cheap gas in a Porsche?
Am I the only one who answered "Absolutely; gas is gas"?
"Goodness me, how unlike the FBI to abuse the trust of the American public." -- The Onion
I have lately wondered how much is enough for a modern computer.
My question is, what is the minimum for a modern computer. In my case it is a XP 2800+, 2x120GB HD and a graphics card top of the line 8-12 months ago and a DVD-/+RW.
Another vote for Sparkle, their power supplies have done well for me. Lots and lots of 3.3V amps, which is pretty crucial these days. They're quiet, stable, and are still among the least expensive.
...
I'm not a power supply designer, but I do have some experience with system power supplies and their affect on system operation/reliability. If I were deciding upon a power supply for my system (or product), I would carry out the same testing as in the article, but also measure the following four parameters:
1. Initial Power Up overshoot/ringing/stabilization. I would hope the supllies powered up with a basic RC curve "POWERGOOD" becoming active when each of the supplies are within 1% of their targets.
2. Transient response. This is different from the "Load" test, it would look at how the power supply worked when it went from minimum load to maximum load and back again. Say starting up the disk drives, CD-ROM and change the fan speed at the same time.
3. Transient response across supplies. What happens if there is a large transient on another supply. The different power outputs in modern power supplies are not as separate as you might think.
4. Power down characteristics. Again, this should be a smooth RC curve with no overshoots or ringing. The high power positive voltage outputs should never go negative.
The first and last parameters will be an indicator of how "gentle" the power supply is on the components and whether or not there is any danger of having them overstressed. The middle two parameters would indicate how reliable operation of the PC would be and whether or not you would get power supply induced lock ups or glitches.
Power supply design is more art and component management than strong engineering application. Modern PC power supplies really are a result of iterative cost reduction and learned experience. A lot of "common sense" ideas are just plain wrong when applied to high current output switching AC/DC converters: I have learned that heavier is not always better and is often an indicator of an inefficient design. Fires are not uncommon in PC power supply testing and development and choosing the best power supply design is often a case of figuring out which company could best understand what the ashes were teling them.
myke
Mimetics Inc. Twitter
Power supply unit (PSU) in modern PC is much more complex than what you think. Also, switching PSUs can be designed in so many different ways with so many different parameters in mind that simply refering to the weigth of the iron in the coil is meaningless. About the compoenents, I don't think that better componenets should necessarily weight more (why should a better MOSFET weight more than the other one??) Generally speaking, as the CPUs are more power hungry today, Graphic cards consume so much power that they need a dedicated connection to the PSU besides what they get from the AGP bus, modern HDDs consum so much (and get so hot) and even RAMs in high-speed systems are power hungry, exceeding the classical 300W is nothing strange, considering the fact that you always need a margin for the safety (usually 85% of the rated value) and place for future exapnsion. And did you know that even in 300W class, may of the cheap PSUs can't even devliver beyound 250W withouth a significant drop in output voltages? A good, high power PSU is really a beast to design....
You would think that, but with the money to maintain a porsche, you could afford the better gas. This is a bad analogy, because the main reason a person would put a cheap PSU in their PC, is because they can't afford it. Hell, my PSU blew not too long ago, and took half my computer with it (motherboard/processor, HDD, etc), and I just rushed out and bought the simplest, and cheapest one. I had too many other things to worry about paying for. I had roommates and friends giving me this spiel about how I should buy the cool looking 500 dollar ones. I just laughed at them and installed my 35 dollar wonder :P
Defender of Microsoft and Communism!!!
http://www.anandtech.com/showdoc.html?i=1841
Does the name Pavlov ring a bell?
I'm an MIS guy for a small company (10 people, 20 PCs -- go figure...) and I always look at PC power and cooling supplies as well as other brands when I'm building machines. I think they make great server supplies or swap in replacements for older machines at the very least.
I have also used those guys for obscure CPU cooling fan options (try to find a quality replacement CPU fan for a Pentium Pro 200)! They stopped stocking them, but offered to make one up for a very reasonable cost -- I went with a different solution, but they were quite helpful. I have purchased several CPU fans from them and none have yet died.
I usually go with Antec power supllies for new workstations because, in addition to running well, they come standard in good Antec cases that I'd want for a workstation anyway.
I'm thinking about it, therefore I might be.
A/C ripple would be 60Hz (or perhaps some harmonic.) A 10ms sample is _woefully_ too short to see it.
... it is my understanding that switching powersupplies shift the frequency to something substantially higher (1-10k Hz region.)
... approximate amplitude was the only conclusion you could draw, but to say "look, A/C" ripple noise is just plain silly ... especially as the A/C ripple would be so much larger than the 10ms sample duration.
Also, of more interest in a switching power supply than A/C ripple would have been the ripple from the power supplies own oscillator
Take a long (say 1 second) sample at a decent resolution (at least 120Hz for a A/C ripple, perhaps 100khz if you care for switching ripple) perform an fft, and look for the spikes at 60Hz and whatever the powersupply switches at.
What they were showing was meaningless noise
I don't know why, but this graph just makes me laugh!
That's true. The hdd motor and head positioning is usually running on the 12V supply and its current profile is on/off at fairly high frequency.
We used to estimate power supply quality by weight. The heavier, the better, since it meant they had more iron. Bigger transformers = better magnetic storage = better voltage stability. Now the switching frequencies are high enough that you don't need big iron cores. But you do need a switching frequency that is a lot higher than the load current frequency. Otherwise the 12V won't be stable. Not that they will tell you the switching frequency in a spec.
I'd like to caution slashdot readers to not get sucked in to posting on the tech-report message board. It's the most depressing collection of blinkered rhetoric it's even been my misfortune to stumble upon, and I'd hate to see that kind of lunacy keep people from reading and posting on slashdot itself.
The cheap one that came with my case overloaded and the power connector fused to my mobo! I always wondered why my voltages were always off and why the damn thing wouldnt do a cold start sometimes. This was a "400watt" model. So I was out both a mobo AND PS. I replaced it with a pricey Antec 550W PS, which should last me for years.
Which one will give me the best framerate in Quake?
Outdoor digital photography, mostly in New Engl
well my no name 400w (~50$ back then) psu blew up and took my asus a7m mobo (more than 50$ bucks) with it.
so go get a real psu, if a cheap one fails chances are its not the only thing you have to replace.
I consider you lucky. The PSU I originally put in my computer was apparently really horrible. Every time I turned on my computer, the system would crash within a few minutes and I'd have to restart, after which it would be fine until I turned it off next. This went poorly diagnosed for over a year. Eventually it started getting so bad that you could occasionally, and then frequently, hear a click that I eventually figured out was the HDD turning on or off.
When it got so bad that I could rarely boot my machine, I replaced the HDD with a much bigger one. In keeping that spinning, the PSU luckily burned itself out. I bought a new one off newegg and since then there have been no problems at all! Never underestimate the lameness of a bad but working PSU.
If you get the foldable waterproof keyboard you can wash it off to turn stickey keys off again.
Rinse, lather, repeat
I don't know if you'd want one of these top-of-the-line power supplies, but you definitely want a decent one.
About three years ago I bought a case without checking the power supply in it and after about a month of operation my mainboard died. I blamed the mobo (it was also a cheap brand), and replaced it with a really nice one. That one lasted about a year, but was really flaky the whole time, especially the onboard Promise ATA100 IDE controller which had so many errors that I stopped using it. When I decided to buy a new machine, I bought better stuff but I (foolishly) replaced the mobo in that system yet again and gave the thing to my wife. Where I'd seen minor instability and annoying failures under Linux, she saw daily bluescreens with Win2K. Finally I bought her a new power supply and all of the problems went away (well, she's still running Windows, but I'm working on that ;-) ).
So, at the end of it all, I'd say the $20 I saved on that cheap power supply cost me two motherboards.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
At my home, I suspect that occasionally a decrease in voltage happens for some tiny time segment (a millisecond?). Anyway, some PCs are not effected, but some are turned off and on.
I wonder whether this has to do with the quality of the power supply unit or - some PC's architecture is more sensitive than other?
I just scanned the article, but I saw no mention of testing for line regulation. Maybe I'm just old school, but that used to be an important factor. Oh yeah, just thought of another one. Home users might be interested in knowing just how much noise that power supply is injecting back into your mains voltage. Switching power supplies are noisy little beasts.
Is it worth buying two cheap-o power supplies that cost less combined than an expensive one so you have a spare?
Would you rather buy a pair of $40 PSU's, have one crash 12 months in, lose all your data due to faulty power to the hard drive, then install your backup (which will likely crash also, as it's in the same system)? Or would you rather spend $120 on a quality PSU, not lose your data, and probably never burn out?
I think a bit of money is worth it because over two years, the extra $40 will hurt you a lot less than losing all your data would.
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Indeed, I was disappointed that their testing regime didn't include any disk seek stress tests; a test which forced two disks (or more) to simultaneously seek from track 0 to track N would would exercise the PSUs' transient capacity really well.
Many years ago, a development system I was using had a cabinet with four disks in it. Every once in a while, during parallel makes, all four disks would spin down simultaneously. Eventually, we discovered that if all four drives were told to seek simultaneously (easy to do on a SCSI bus), the resultant load on the 12V line would pull it out of spec, the power supply would shut down, and the disks would spin down (releasing the overload and allowing the power supply to come back up, hiding the evidence). Since this box was a kludge, we "solved" it with a big, fat capacitor on the 12V line (next to the drives) to handle transients. (Which probably reduced the power supply's lifetime due to power up transients, but who powers down development systems?)
Modern disks do draw less transient current during seeks, so this isn't quite the issue it used to be, but it is still a source of stress they ought to have checked.
Anandtech has had a similar piece online since last week.
http://www.anandtech.com/showdoc.html?i=1841Neither of these stories is /. worthy. Must be a slow day for FSF or Microsoft bashing.
an ill wind that blows no good
The article looked looked nice until it got to the part with AC ripple voltage. It says it shows a 10ms interval, and then gives graphs going up to 100k nanoseconds. And a single AC cycle is rather more than 10ms. All in all, this kind of thing makes it rather difficult to interpret the graphs in any way beyond 'ooh, that's a bit noisy'.
I suppose you can see a regular pattern in the Ion PSU, but that's probably not so much the AC as a result of it being a switching PSU.
Still, I think worrying about things like the voltage ripple is somewhat over the top. More important is stuff like getting the decoupling near the chips right, and that's not the PSU's problem.
PC Power & Cooling. 'nuff said.
Or use the Ctrl-AltGR-Del alternative combination on the right.
Well lets see, I had one of those cheap no name powersupplies in my last system. One night it blew up. That in itself was pretty cool, had fire and shit shooting out the back of the case, smoke coming out all the holes. Now for the uncool part, every thing in the system was toasted. About 1500 bucks worth of system up in smoke.
I guess it could happen with any powersupply but in this Beast I bought the one they recommended last year.
Supporting World Peace Through Nuclear Pacification
Actually the power supply could no good with badly
designed system components that are supposed to
produce lot of transients in the first case.
As long as you have well designed components and
if the design takes care of the power supply bumps
at the board/chip level, there is no need for an
extremely clean power supply. The quality of the
components that go into the power supply and the
internal heat dissipated in the power supply are
indicators of the design/build quality, which will
not show up immediately, but might be in a matter
of months if not years. Also a sufficiently overrated PS will be better than a PS with low
power rating. All the electrical ratings do no
good than providing a minimal guarantee of the
stable output. So here are the few tips to getting
a decent power supply:
i) Get one that is sufficiently overrated.
ii) Check if there is lot of heat generated under
heavy loads(the size of the PS fan is an indicator
in most cases, except in a generously overdesigned
PS).
Uninterruptible power supply, not United Parcel Service. Can you get away with having a cheap power supply if you have a UPS?
:)
I learned the importance of having a solid power supply when I moved to the unstable New Orleans power grid (damned third world around here). I fried 2 cheap ps's. My roommate went through 2 motherboards, and we've gone through 3 routers and 5 network cards. All of this in a year time frame. I finally got wise and bought antek for like $80 and a UPS for maybe $150 and I've been stable ever since (and I can continue playing GTA when a fuse blows. That's right, a fuse) But I have no way of knowing if my ps is that much better or if the UPS is what did the trick.
Also, any ideas on how to shield a cat-5 so a spike in electricity doesn't fry my network card and possibly everything else? I might go wireless on my desktop, but wireless is soooo slow compared to cat5
----
Squirrel
Another item I found lacking is that they only tested one power supply of each type. If you happen to get a bum PS from one manufacturer, you can draw faulty conclusions from the benchmark. They should have at least done two of each to see if there were wild differences. The Ion PS, which performed poorly in the A/C ripple (whatever that means), could have been a bad Ion PS. We'll never know...
Under capitalism man exploits man. Under communism it's the other way around.
Someday, my powersupply will burn down my house.
In order to turn my computer on, I must first flip the power-supply switch (I always keep it off just for safety or something). Then I push the front power button. Computer comes on. Drives boot, fans come on, etc, but no screen. No POST, no beeps. I then have to 'rock' the power switch in the back where the computer browns out and only then if I do it correctly will the machine boot. Been doing this for a year and a half now, everything's ok.
Might be more stable and safer with a functional powersupply, though.
Job? I don't have time to get a job! Who will sit around and bitch about being broke and unemployed then?
Here's one easy thing that you can do to minimize the impact a power supply will have on the internal temperature of your case...
You'll notice on most power supplies that there is a fan venting heat INTO the case. An easy solution is to reverse the fan(s) in your power supply so that they pull air from inside the case and vent it out the back. This is especially handy when incorporated with a case fan in the front of the chassis that moves cool air into the case. This establishes a nice flow of cool in the front and warm out the back.
Reversing the power supply fans is usually one of the first mods I make to my PCs when setting up the cooling system.
Skiers and Riders -- http://www.snowjournal.com
Either I haven't read the comments up to this point carefully enough, or nobody has said anything about line current, and its effect on PSU performance. The article didn't have any tests for it either.
I know we all power our machines through UPSs with nice clean conditioned power, but most of the unwashed masses plug theirs right into the wall, with all the attendant brownouts, spikes, and neat things that happen during thunderstorms.
Too bad they couldn't test the performance and robustness of those units under degraded line current. Would be much more useful information for me than what color the connectors are.
Not trying to dispute your claims here, just relaying my personal experience. I have two PCs with no-name power supply units. One PSU has lasted over two years with no problems. The other PSU is only about 9 months old (entire system is only 9 months old) and is exceeding my expectations. I'm only 5W below the 350W ratings on both PSUs, too. I paid $50 for one and the other came with my $30 case. So, to answer the grandparent's question, I do think it would be worth buying two cheap PSUs.
right on - totally agree 100% - I always use PCPwrCooling for all PSUs, CPU Fans, and case fans. Good company, damn excellent products, fast delivery, easy-to-use no-nonsense website, good support (people are smart and friendly). I never even consider alternatives because PCPC stuff always seems 'industrial strength' next to almost everything I compare it to (except maybe, rarely some TOL Antec or Sparkle). No better value than PCPwrCooling out there today. Period. And, when I see that a reviewer has not included PCPC in a 'review' of PSUs, I know the 'homework' was not done.
IMO the biggest problem with most power supplies is the terrible power factors. Power factor is what fraction of apparent power is actually used by the load. Typical PC power supplies have a power factor of 0.5 to 0.6 -- pretty poor. Bad power factor means that fewer machines can operate on a given circuit. PC power supplies and fluorescent lighting are the biggest contributor to circuit overload in office settings.
You fucking better believe it!
I second that. My PC Power and Cooling PS is the only original part in a system I built for myself 5 years ago. I got so sick of listening to the cooling fan bearing (bushing?) in POS supplies die, so I laid down the cash for a quality unit. I think in the past five years, my system has been turned off for a total of 72 hours or less. My PS still runs like a champ.
Entrepreneur : (noun), French for "unemployed"
All I can say is my machine is using a $15 case/powersupply and it has massive uptime for the past year. In fact the only time I need to reboot is when I install something that insists on it. Running win2k on a 1.7athlon. It NEVER crashes and I run a huge variety of software.
I am sure their analysis has some merrit but it also has to do with the load and the oversizing of your PS capacity. Always but with some "headroom"
I had an Antec 380 that actually *caught fire*. Sparks were shooting out of it until I managed to dive at the UPS and kill it. The overload protection in this power supply was faulty or something.
The fault occurred when I redistributed the power leads inside of the case so that a previously unused (and faulty) lead was plugged into a perfectly good hd.
My living room filled with acrid smoke as it was burning. I tested all components on a different power supply, and they all were ok.
A new power supply worked fine with all of the same components.
Miraculously the antec was properly grounded and *none* of the components in my computer was fried.
Though there was a manufacturing defect, Antec's design kept my computer from being otherwise harmed. Thank you Antec!
To improve their design, they should put a fusible link in front of the transformer.
L8,
AC
I believe the charts are mislabeled. They say nanoseconds at the bottom, but the clear 60 hz signal on the cheap ION one would be correct if the units were microseconds.
I found that with certain BIOSes on my ABIT BP6, if I had disks plugged into different onboard IDE controllers (UDMA66 or the standard), I'd have to do the same thing. I reflashed the BIOS (again) and the problem went away. Go figure. It's a weird one.
I want to delete my account but Slashdot doesn't allow it.
Gees, I run my systems for years without a single memory error (mix of parity and ECC systems under my control). What the fuck was AnandTech doing wrong?
"Eventually it started getting so bad that you could occasionally, and then frequently, hear a click that I eventually figured out was the HDD turning on or off."
.75 sec apart, and between them the system freezes (no mouse movements, etc.) However, I've had no PSU or stability problems to speak of, other than the standard occasional wonkiness that comes with win98.
I've got a similar mysterious clicking noise in my system. Every once in a while, I'll hear two clicks, about
What could this be?
Speaking of Magic Smoke ...
I was recently forced to unplug/restart my DSL modem and router. The cords for each fell off the surface where I had the router and modem sitting. When I reached down I grabbed the wrong cord and plugged its end into the router. It fit, of course , but -- Bang! Light Show! And Magic Smoke.
Seems different adapters put out different voltages. Who knew?
Any EE or student or graduate worth their salt knows that Anandtech article is total shit. Don't bother with it.
You mean line VOLTAGE. Think of the voltage as the height of a waterfall, current is how much water flows over it per second. Raise the height, raise the potential energy. God, I had Senior year Uni students who confused the two things!
I want to delete my account but Slashdot doesn't allow it.
Is there something that these power supplies contribute towards overall system stability that "cheap" ones don't?
The short answer is they give you added margin against worst case power flucuation, load changes and temperature extremes. An old engineer I once worked with used to refer to such margin as "belt and suspenders". He'd explain that nobody ever lost their britches wearing both a belt and suspenders.
The Zalman has superior voltage regulation and ran cooler. If you have a system that is very important to you, you don't want a crappy power supply glitching your motherboard because it's output is on the the low end of the tolerance band, it's load regulation is poor and the system temperature is high. Lets say you're burning a CD. That will cause step load changes in the +12 output due to the disk drive activity. At the same time, a line voltage sag event occurs on the incoming AC power. Now the power supply has to slew that transient as well as the load. This can cause an el-cheapo brand x power supply to dip the +3.3V and/or the +5V dangerously close to the minimum guaranteed high voltage level for some of the chips on the motherboard or other devices. On the motherboard, there may also be considerable voltage drop in the printed wiring before the most remote IC. Whats worse is these kinds of problems tend to be intermittent and they can manifest themselves in seemingly random ways.
Wansu, th' chinese sailor
If I have computer, and it has a 200W power supply, if I replace that power supply with a 500W, will the computer consume more power from the wall? Like, will my exectricity bill for the computer be 2.5 times more expensive?
:)
Do I only use power to meet the demands of the devices? Like if I have a 200W supply, but only have devices that use in total 150W, do I still draw 200W from the wall?
I hope you understand what I'm asking, boss is lerking, gotta be quick.
I used to run a cheaper PSU in my old "Duron" box. Not, Durons are (or were then, not sure about not) inefficient power-gobbling little monsters, but the PSU was rated such that it should have been more than up to meeting the demands of the chip. However, odd things started to happen. Notably, if I were using both my Burner and DVD-ROM at the same time (i.e. copying a disc), sometime later one of the drives would go offline. The drive would simply cease to exist, and would not be found by the system (didn't eject right either) until I did a shutdown and restart of the system.
In summer, I also had to worry about my CPU overheating. Since then, I've got a better power supply, and no more CD-ROM malfunction. With the added PSU fan, my CPU no longer overheats in summer either.
Seriously, if you're going to shell out several hundred for a top-of-the-line video card, or > a grand for a nice system, then at least have the sense to put a formidable power supply in it.
High octane gas has a higher ignition temperature. It's used in performance engines because they, for efficiency reasons, are designed to generate higher cylinder pressures. Higher cylinder pressures means higher temperatures (basic thermodynamics).
Having said that, high octane fuel actually contains fewer available BTU's than regular -- it's a trade off
Older cars ping because carbon deposits form on the valves. These deposits hold heat and become hot spots which can pre-detonate the fuel. The "ping" is the sound created when the wave front from the pre-detonated fuel slams into the wave front from the fuel ignited by the spark plug. This creates high pressure zones (at the intersection of the two wave fronts) that damage the pistons and valves.
Using higher octane fuel in older cars with worn engines reduces the "pinging" because the fuel's higher ignition point exceeds the temperature of the carbon deposits (so the carbon can not ignite the fuel). You can often achieve the same result by reducing the ignition advance -- which incurs the negative side effect of reducing power.
Whats with the oversized PSU plugs that turn my 8 point power strip into only 4 Cant they 1) put the plug component(standard size) out of the transformer component. 2) not get so darn hot 3) be intelligent enough not to drain power if there is the device itself is switched off.
Sorry, I used (US) electrician terminology--they generally talk about the stuff that comes out of the wall as current, e.g., "two-twenty three-phase current", even if it's technically a misnomer.
I know the difference between volts and amperes, ohms and henries, reactive and resistive loads, ground planes versus ground loops, SWR versus SNR, etc.
And no, voltage is NOT the only thing that varies at the wall outlet due to environmental conditions.
Let them do all the work.
Of course you can route one of your internal power connectors out through an unused pci slot opening so you could do this even if you didn't buy the Antec PSU.
On the next system that I build, I going to buy extra molex connectors and redo the PSU wiring harness. There's a lot of spagetti on those PSU and it just gets in the way of a clean wiring solution. Plus I'll have external molex connectors for my external drives.
I'm writing this on an Athlon XP 2500 (oc'ed to 2.09Ghz) crammed into the cheapest micro atx case I could find. The case came with an even cheaper, measly 165 watt power supply. The system also contains a Gefore TI 4600, a 120GB HD, and a DVD/CDRW drive. It runs 24x7 in an attic where the ambient temperature has been between 85-100 degree F for the past few weeks. It's the fastest & smallest system I've ever owned and it's never crashed once. I can say with some confidence that none of the 20 or so machines I've built over the years using the cheapest power supplies available, have ever had stability problems that I could blame on the power supply. In my experience they usually either work or they don't. (I've seen a rare exception or two on the job and those were always with more expensive power supplies than I'd purchase for myself)
I personally, have taken a cheap, no name power supply and changed all the caps in it. result: much better power supply.
I always crack open power supplies to see what brand caps they use, because I know from experience that its caps failing in power supplies that kill them.....
and your computer.
I have seen a brand new brand name power supply use the WORST caps.
so, you can compare these brand name supplies all day, but there might be a cheap one thats more stable, if not better made.
shop around, you might be suprised.
I was a little surprised to see this too. But what they did was set their memory test tool to write a set of values to the memory, wait six hours, and then compare them. What I don't know is if they (or how they!) disabled the ECC circuitry on the DIMMs themselves to prevent it from correcting the errors so their testing software could see them.
Presumably, these errors come from cosmic rays and radioactive decay (worse if you live in a masonry house!).
One thing I can personally agree with in the Anandtech review, is that PC Power & Cooling make some awesome power supplies, but they are really loud - it's like having a hovercraft in the room with you.
Chip H.
Maybe they didnt use ECC memory???
Here's an example. About 20 years ago while working for an electric public utility, my employer had purchased some line filtering equipment from a small engineering company. The idea was to place these large transformer-ish devices on the power mains of customers suffering from voltage spikes caused by other industrial users sharing the same power line. Initial testing showed that the filters - though very, very heavy - had no effect on the quality of the line. In frustration, they X-rayed the filters to see what was inside. The X-rays came back with what looked like a bucket full of rocks. The images were used as evidence in a civil suit against the small company that produced and sold the "filters". -rick
You're new here, right?
It is unfortunate Seasonic was not included in this comparison. This review explains how the Seasonic Super Silencer 400 is cool and quiet, a true 78% efficient PSU with Active PF.
What is "crosstalk" in a DC power supply? Do sudden demands on 12V greatly affect the 5V line?
Buying a backup infers that you reasonably expect the first to fail. That failure can mean much more grief than just replacing the failed PSU with it's backup. The question is - do you want to gamble with your system hardware, or your data? Each person and situation begs a different answer.
On a more or less hard core tech forum, they expect you to know this going in.
But it wouldn't have hurt to have included a paragraph on why it matters. It's quite possible to be in their target audience and not have a electronics hardware background.
Send a letter to the editor telling him what you told us.
Tech Public Policy stuff
Thank you both Fendel and Jonsey!
Quality internals. Go open up your normal "freebie" power supply and look at it carefully. Is there a proper amount of ehatsinking to keep teh mosfets cool or is it just enough to keep them from burning out? Are the capacitors of good quality and capacity, or just barely passable? Then look at the soldering jobs, has the pcb even been cleand of flux? These premium power supplies are built to perform even when something goes slightly amiss, like a worn-out fan isn't putting out the airflow it used to, or the innards are dust caked from 500 days of non stop service in a home enivronment. Once you see the build of a commercial grade supply (telecom equipment especially), you will start to see some similarities in build quality. Sure the pc supplies are all very crude technology in comparison, but the quality craftsmanship will show. This quality is a major part of reliability. Poor solder joints will only cause something to fail early, and recycling of mechanical parts (read: fans) is not going to help any either. I'm not saying all makers have done this, but I have opened up a brand new PSU before to find a fan 10 years older than it inside. It worked, but the only reason why is because of the 'fix' done to it's sleeve bearing...namely it had thick grease inside...not good. Then there's how stable the voltage is, voltage spikes practically stab your components to death. You won't see it until something breaks though, so to most people it's "ok". Another part is for gamers, gaming systems are their hardest on the 3.3 and 5v rails, actually extremely hard in many cases. Some modern AGP cards actually pull so much current that they have to have molex plugs on them since most mainboard's can't put that much out without risk of burning a trace. CPUs run off the 5v rail, and when a CPU can put out up to and maybe over 60w of heat, you can be assured over 100w is going into it...thus the need for a beefy power supply. That extra power guarantees you won't run over and posibly have your system lock-up. I have been a fan of Antec supplies for years, even their cehap ones are very good quality. You can get a 300w for about $35 (I reccomend 300w miminmun for any modern ATX system), I use a truepower 380. It costed me about $75, and is by far the quietest psu I have ever owned. When a power supply puts out the same if not less noise than your hard drives it's a beautiful thing.
Well congratulations on your good luck with that junky 165W power supply, but I have my own data point. My system used to be a 1Ghz Duron (Morgan core) o/c'ed to 1.33Ghz and Geforce2 MX. The PS was an Enermax 300W that came with the case. I upgraded to a Ti4200, and it started locking up in 3D games. If I ran the CPU at stock speed, the lockups went away. I ended up buying an AthlonXP 2200 and a decent 360W PS (CWT) and no problems since. Very frustrating but fortunately no permanent damage.
Is the Zalman's ZM400A-APF 400W power supply goth? And if so, is it a threat to our children? Should it be banned like guns at school? I don't want PSU's making kids into terrorists.
Maybe hold control and alt with your index finger and hit delete with your middle finger? Or thumb and index finger, respectively, if you only have a left hand.
Alternatively, you could get a Mac.
I broke my left wrist a few days ago and have been typing one-handed since then. I haven't had any major problems other than having to type very slowly search-and-peck style, so I don't really have much sympathy for your complaint. Sorry.
I found the meaning of life the other day, but I had write-only access.
For a power supply to be even considered these days it must have Power Factor Correction. With a PFC chip, the power supply is forced to accept a sine wave, which basically brings the voltage in phase with the current.
This vastly increases the efficiency of the supply, reducing heat output, and cuts down the impact the unit has on the rest of the mains supply. This is of high importance in buildings with 100+ computers. Without PFC, the AC sine waves look more like sharks teeth.
In fact, in many countries it is illegal to connect a regular non-PFC unit to the grid.
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
It always struck me as an unfortunate name for a device with 120/240 volts pulsing through it. One loose cable and it will really Sparkle.
Kinda like the Quantum Fireball, runner up in the unfortunately-named-PC-hardware contest.
For examples, I would reccommend you check out http://www.tomshardware.com/howto/20021021/index.h tml where they tested 21 PS's to the limite with a wide variety of effects.
Gotta move
Check out the pics here. Pricey but really cool looking.
Also, the ability to filter noise out of the AC helps with stability...
I've noticed that browsing with treshold 4 filters out all AC noise. It helps with my mental stability.
Antti S. Brax - Old school - http://www.iki.fi/asb/
I hope this gets modded up, it needs to be said:
No offence to anybody, but there are so many people posting here that are completely wrong its hilarious.
I especially liked the guy who thinks power supplies are handing out "watts" to their respective regulated voltage supplies..
When I first built my Asus A7V roughly 2 years ago, I bought a Sparkle 300W PSU from Fry's. Was one of those that was P4-compatible. Had massive stability problems. System would lock up, not reboot, not cold boot. Basically a big headache. On a hunch, I returned the PSU and ordered a PC Power & Cooling 300W. Very stable ever since.
When I buy a PSU, I've never paid much attention to the brand, but I always choose one that's heavy enough to brain a sheep, and has enough power leads to pass for an octopus (the better cases, even no-names, also come with decent PSUs, so finding 'em isn't too difficult). None is the least bit flaky even after years of well-loaded use (frex, the one in this box is 9 years old. Yes, my PIII is of the AT persuasion. :)
Conversely, a few years ago someone gave me a stack of truly cheapassed cases, with the most minimally-made PSUs. Now, these were all brand new and had been in use only 3 days (at a convention), powering only a 386 mini-motherboard, a basic video card, and a floppy drive -- hardly a stressful life. Yet out of the six machines, 3 failed to ever power up again, another is flaky, and another's fan croaked. So out of the six, only one fully survived its first week of work.
Goes to show how that extra few bucks up front can save you a lot of cost and trouble later, or maybe even sooner!
~REZ~ #43301. Who'd fake being me anyway?
Price doesn't necessarily mean much, tho. Often it magically goes up when the brand name goes on. And a few months or a couple years is a very short span for a *good* PSU.
Frex: There was a particular generic AT midtower that I bought by choice, and I've had a bunch of 'em. They were about $35, and came with a good heavy PSU (tho of various ratings: 230W, 250W, or 300W) but no two had the same brand label even tho they look like they come from the same plant. They've all been perfectly reliable, and not just for a couple years. The one sitting next to me has been running 24/7, under a fully-loaded system, for over 5 years now.
My other 24/7 box has a 300W AT PSU from back when 300W was a special-order item (can't think what brand it is, if any, but at the time $50 was a stiff price). It's been supporting a well-loaded system for 9 YEARS.
And it's not my oldest (that would be from 1986), just the one that has the most years of 24/7 service and has worked the hardest.
On the other end of the scale are some truly crappy cases/PSUs someone gave me, that had an 80% death rate after only 3 days service! (See previous post, where I detail their short and sordid lives.)
~REZ~ #43301. Who'd fake being me anyway?
For two years I ran this old 486 on a heavy-ass 250W LiteOn PSU (the PSU was two pounds short of the entire weight of the system) and it never experienced any downtime more than 5 minutes (caused by power service interruptions). That 486 was a third-hand unit and is now well over 9 years old, and has since been passed on to another person who is still getting plenty of reliable use from it (still going 24/7). I have no idea how much load is actually on that particular PSU, however, as I never cared to measure.
It seems to me that the AT days were when you could find a good PSU rather easily. I've had one AT PSU go on me, and all the others (I've lost count, but it's a good many) still work quite well.
Power supplies in the AT era were about the LAST component you expected to go bad. They just kept going and going, and units that were bad from the gitgo were rare (until the very end of the AT era). But in those days, profit margins weren't so thin, and manufacturers could afford to just make the unit however it needed to be made. Shaving off an ounce of shipping weight wasn't worth anyone's trouble.
Nowadays it's different. Most components are shipped in from China, largely by air freight, where an extra ounce per unit adds up to multiple dollars in freight charges. And the market has become much larger, and overall less selective as everyone tries to save a buck, so saving a few cents can mean you get the sale and not your competitor.
I remember when we expected a monitor to last a decade too. Those days are gone as well, for similar reasons.
I have some idea how much load is on the 486, er, P90, I mean P3-550 [g] because when it was fresh and new, we added one too many devices, and the original 200W PSU refused to power up. Hence its current 300W unit. That PSU and case weigh more empty than newer ones do packed full. Just in case anyone wonders why I hunted down an AT motherboard (Tyan) for its P3 upgrade... at the time, decent ATX cases/PSUs were scarce and VERY expensive.
Clone cases/PSU have improved again lately, or at least now you can find one quickly and at a good price. And once again I've settled on one particular no-name, since the cases are nicely made and their PSUs seem decent enough, if not top of the line. I don't think it's coincidence that this case and its variants have become the most commonly used among local clone shops that stake their reputation on a reliable product.
~REZ~ #43301. Who'd fake being me anyway?
I, for one, can't stand sparkle. I wasted a good three motherboards on three different sparkle power supplies, but in my latest incarnation, I went Antec, and I haven't looked back since.
The Truepower series is truly fantastic. My 5v, 12v, and CPU core voltages are all on target (My sparkle PSU had me past 2 volts on an Athlon TBred B chip), and I haven't had a single PSU-related error yet. I just wish there were less connectors, it's really making my box look messy.
I will now redundantly add my name to the end of my post. You know, in case you forgot me or something.
Higher octane has one use and one use only, that being to allow an engine to run higher compression/more advanced spark timing without pre-ignition (detonating/pinging).
I browse at +5 Flamebait- moderation for all or moderation for none.