Power Supply Torture Test

An anonymous reader writes "With the latest batch of power hungry graphics cards, the PSU in your computer is more important than ever. If you're looking for a new power supply, check out this group test. They've tested 19 PSUs - some good, some bad and some downright explosive!"

Comments

350W Power Supply

[JohnHegarty]

If you ask me (and i think you did) the power rating on power supplys useless. I have seen 300W power supplies (good ones) with better power output then cheap 400W.

Its the same scam the PMPO ratings on speakers.

Re:350W Power Supply

[gweihir]

Its the same scam the PMPO ratings on speakers.

Not quite: PMPO is honest. People just don't bother to find out what it means (almost nothing).

Writinng 400W on a PSU that fails at 380W is a lie.

Re:350W Power Supply

[imsabbel]

its not a lie, at least not more than pmpo.
I have seen 250W pmpo speakers that ran of a 10W psu...

You could also argue that the psu has 500W: if you only need 12v, you can get 20 amps, and if you only want 5v, ... , making it able to deliever 500W, just not all at once.

I would say that this isnt anymore lying than pmpo (both sucks)

Re:350W Power Supply

[eric_brissette]

Yup, that wattage rating is pretty much for marketing purposes. Instead, add up the wattage delivered by the three "+" volt lines which will give you a better idea of the actual maximum power output available to your components.

Even then, cheaper PSUs tend to be a little liberal with these figures and many burn up when approaching their advertised maximum load.

There are other factors such as voltage stability and efficiency that should also be taken into consideration.

I guess the moral here is that when it comes to PSUs, brand name can be important. Enermax and Kingwin PSUs have always treated me well, and Sparkle has also for a less expensive alternative.

Re:350W Power Supply

[gl4ss]

well.. then again: don't buy shit.

i'm torturing an enermax 303watter now.. drawing ~25amps from the 12v line and it's holding at 11.94v(no, it's not driving a computer and quite frankly i expected it to break or shut down but it hasn't done so yet).

if the highet watt rated one feels lighter than the proper psu's cardboard box you'll know it's a hoax.

Re:350W Power Supply

[imsabbel]

Yeah, i dont.
I wasnt bothered because of the dismissal of the bad psus, but of the defence of PMPO (which really sucks bad).

I, too have an enermax. I used to hate them because my first enermax was one of those first dual fan ones with a wrongly placed thermal sensor (intants turbine sound), but the new one i really liked.

Upgraded from a 450W noname to a 365W enermax, because the noname could power 8hds, but the enermax can.
But there was no lying involved. the 450W one had 330W combined power on 3&5V, and only 14 amps on the 12V rail, the enermax has over 20 on the 12V.
So just different specs.

pling

[private Burrito]

In soviet russia power supply torture tests you

What happened?

[michelcultivo]

Maybe the guys at Trusted Reviews don't use the recommended Power Supply of it has been /.ed

Mirrordot link

[PornMaster]

Mirrordot link to Trusted Reviews power supply review

Good, I guess...

[Dragoon412]

I always stress the importance of getting a good power supply when I give advice for building PCs, but it seems like something people are largely willing to gloss over, and just go for some cheap no-name with high wattage. It's nice to see a review for these, finally...

But, of the companies on here, I've never even [i]heard[/i] of Tagan, and it seems a bit sketchy that Tagan wins best honors in their review... which was conducted in Tagan's lab.

Furthermore, why aren't Sparkle or Antec power supplies tested? Along with Enermax, they're widely regarded as some of the best around.

Pity they didn't include...

[hcdejong]

noise measurements. A l33t PSU is no good if it sets up a howling gale in my room.

Re:Pity they didn't include...

[antiMStroll]

The Seasonic which made honourable mention is almost dead quiet. The entire inside is one large fan, the largest I've seen.

Can you look at this for me?

[markmcb]

In college, I was the guy to go to if you had a computer problem. One night, one of the football players comes knocking on my door, "Hey Mark, my computer's acting weird, can you come look at it?" I agreed and we walked down the hall to his room. Strangely, the machine was off so I reached my hand out and turned it on. I jumped back at the sound of a loud pop and the sight of flames and smoke coming out of the back of the power supply. Immediately, I reached for the cord and pulled the plug.

"So can you fix it," he asks in all seriousness. I just looked at him in total disbelief and said, "Man, your computer was just on fire. No, I can't fix it."

He was really good at football though! :-)

Damn

[GigsVT]

That page is annoying, it keeps jumping up and down while I'm trying to read it, because of that stupid javascript ad.

It's kinda silly anyway, the article's premise is that they got access to this $20,000 power supply testing equipment... A set of simple $10-$20 high wattage load resistors would have worked just as well.

A $1000 scope might help if you want to catch a load dump overshoot, startup transient, or ripple, but it looks like they aren't even concerned with such important specs of a power supply, specs that could burn our your system.

Anyway, some testing is better than no testing, which seems to be the norm for computer power supplies, so I am thankful that someone with access did these tests, but it would have been more useful if they had tested more than simply steady state load.

Re:Damn

[Linker3000]

I spent some of my electronics engineering apprenticeship in Unit Test where I had to test 5V 300A and 5V 600A power supplies.

We had a FET-based active load for testing and we had to bolt the PSUs to the load with 1 inch copper braid, put the units in a thick plexiglass/Perspex cage and run them at 110% of rated load for 10 minutes.

When we got busy, one of the other engineers soldered up a ton of wirewound resistors to act as a load and fitted them into a spare 19" rack with a large red 'emergency stop' button on the top to cut off the power. The whole rig looked like a McGyver special, but it worked and I wasn't too afraid to use it-but when we got VERY busy, I was told to forget about bolting on the braids, just hold them in place, wind up the active load to 110% and keep it there for 20 secs and 'that will do' - I refused, much to the annoyance of the Unit Test manager who couldn't actually force me to do so!

The guy who made up the resistor load was really mad - it was the era of the BBC micro and he'd lashed up his own floppy drive, but discovered that he couldn't copy one particular game or program because the drive he was using wouldn't step properly to one of the 'hidden tracks' (or something like that), so he bought an official external drive (for some crazy price - it was 1982, after all), did his copying and then hooked up the ground wire of our PSUs to the chassis of the floppy drive and dragged a wire hooked to the +5v line around all the chips' legs - end result was tons of sparks and one very smoky unit which he took back for a full refund. Apparently he complained bitterly to the shop about the way the drive had suddenly 'exploded'.

This was also the guy that fell over and broke his leg walking across the car park one sunny day - we really couldn't work out how he managed it! He also removed all the light fittings from a temporary work cabin the night before it was due to go back to the hire shop - when the hire company came to pick it up, they refused to take it so our boss called us all together and said it might be a good idea if the light fittings returned 'tonight' - lo, next day they were all back in place.

$20000

[digitalchinky]

Come on, you don't need $20000 test equipment to push a tiny little power supply to the edge of its existance. The first paragraph looks more like a marketing scam.

A nice old 3 inch nail bent up and jammed into the plugs for a few seconds should sort the good supplies from the bad :-)

110v+220v=LOUD BANG

[Savage-Rabbit]

I always stress the importance of getting a good power supply when I give advice for building PCs....

Personally I'm happy if I can teach users to remember to switch the powersupply from 110 to 220 volts when recieving computers from bought in the USA before plugging them into a 220v power outlet. I still have trouble not laughing out loud every time one of those ebay jockeys shows up with a PC/MAC that has a burned out powersupply. It must be really frustrating to buy a PC/MAC for a shitload of money and then damage or completely ruin it because you forgot to flip one little red switch.

Re:110v+220v=LOUD BANG

[Spacejock]

Man, I remember an Atari ST enthusiast back in 1987. He owned the only ST shop in town, and he imported about AUD$14,000 worth of gear for demo purposes (big HD, controller cards, etc - this was before Atari Megadrives. My Megadrive cost me around AUD$1750, so that kind of dough wasn't excessive.) He hooked up a DX7 keyboard with midi cables, both monitors (via switchbox), laser printer ... the whole works.

Then he plugged it in and fired it up.

Pity the external hard drive transformer was 110v, and Aussie power is 240.

A year or so later he could laugh about the way the drive heads were fused to the platters when he opened it up for a look. At the time he was somewhat distraught.

Another less expensive tale - the tech at a computer shop I used to work for ordered in an 80mb hard drive for a customer in the days when 20mb was the standard. (yes - MB. It was a long time ago...) This thing cost around AUD$800 (about US$600 at current prices), and unfortunately the molex socket on the drive was quite flexible and his glasses weren't quite strong enough. So he put the Molex power plug in upside down.

End result: I found him wreathed in magic blue smoke, explaining to the distributor that a sudden fault had arisen with the new and very expensive hard drive.

Antec TruePower 430...

[Goldenhawk]

I was having consistent random crashes - the computer would suddenly reboot (all the way to bios, instantly) with no warning. The only clue was it happened most often when I was doing a disk-intensive task (which meant I had several crashes while the system was writing the FAT... BAD news).

For months I troubleshot all kinds of stuff, to no avail. New mobo, new processor, rearranged hard drives, reinstalled software, new network card, you name it - one step at a time, but no effect. The crashes continued.

Finally I happened upon some similar accounts of instability and they mentioned power supplies. I thought I was okay with a 300w supply and my Athlon. Nope. As soon as I replaced it, instant stability.

Some things to note about my experiences:

I upgraded to the Antec TruePower 430. It's an extremely quiet supply, even quieter than my processor fan, with a temp-controlled variable-speed fan and a second case fan molex connector that also is temp-controlled. It rarely runs above idle, but my case is always cool. That alone was worth the upgrade price.

I was loading the supply more than I had realized: I run dual graphics cards, two hard drives, and two CD/DVD drives. The crashes were apparently caused by the hard drives - it's apparently well-known (in some circles) that the highest instantaneous current draw in a PC is when the hard drive head starts to seek (lots of current is needed to get rapid motion and get the seek times down). So anytime I was doing a disk-to-disk operation - like a backup or CD burning - I was loading the power supply dangerously close to its limit. One step over the line, and the processor would hiccup. Boom, instant bad FAT table and a week of rebuilding.

Finally, this wasn't an overnight problem. I brought it on over time by adding things to my PC incrementally... hey, let's add another drive... hey, a spare graphics card... I can keep the case - it's working fine, right?

So word to the wise: get a GOOD power supply, and get one that's rated well ABOVE your expected average load. Pay attention to those current draw numbers on the hard drives; wattage alone doesn't tell the whole story, and small spikes can kill you.

Be Careful

[serith]

To tie a cheap oem 300watt power supply to a whopper of a PC that you just blew a few thousand dollars on is the biggest mistake most people make, and overlook. Dirty unreliable power supplies that feed your PC are like heart attacks waiting to happen. If you're going to invest heavily into building a new computer, do not over look your PSU. If you do a little research (other than compare maximum power to price) regarding Max power @ watt operating temperature, you'll see that most cheap PSU's are rated say 300watts, but for a nice 30 degree Celsius operating temp. Now let's think about that. How many PC's operate that cool? Also, your better built PSU's will typically weigh a lot more, because they're simply better built. Nice and heavy means beefier power supplies, larger capacitors (to give your board that extra oomph it requires when you boot, or when you load it up), and it might even mean you have PFC included--a Power filter controller. These PSU Companies aren't always out to get the consumer by the jugular.

Torture? I think not.

[NoseBag]

First - I spent the better part of 20 years designing military and aerospace switching power supplies and systems. Admittedly these toys were commercial products, but I think I'm qualified to say the following:

a) purely resistive loads are a poor model for PC load characteristics, as are purely constant-current loads. But the CC load is a tougher test.

b) transient line and load response (or lack thereof) can preclude operation at the steady-stete levels tested.

c) I just skimmed the article as it was loading strange, but I didn't note any specific cross-regulation tests. These types of tests may yield poorer performance measurements. They almost always do.

d) Testing to see if a PS will run at full load is not the same as seeing if it will START under FL. I didn't notice these tests. Likewise Starting at low or hi input is tougher that running at same.

e) we ps designers had an expression: Power supplies are like assholes - everyone has one and everyone thinks they're an expert. The former is true (some folks have two :) )- the latter is seldom accurate.

OK - flame away. I'm gonna go eat lunch.

Power Supply Ratings

[lcsjk]

The power supply nameplate ratings are not based on output power but input power. This is a requirement by the international product safety agencies. Look on the nameplate and you will find the CE mark, a UL mark, and other symbols related to requirements imposed by various countries around the world.

The output power rating, which is what you need for operation, is based on a combination of the outputs that can be simultaneously loaded.

The efficiency of a power supply is also dependent on the load being used. For instance, the main regulation feedback loop probably has the highest efficiency and the other outputs have secondary post-regulators that require more background power to operate.

Power supplies operate from a 120 volt or 220 volt input AC wall plug/outlet and undergo some severe transients at turn-on and turn-off. Some of the supplies have automatic voltage sensing circuits to operate from either of these inputs automatically. Nearly all power supplies operate from an internal 340 VDC. This voltage has to start from zero and return to zero when unplugged. Most present power supplies have a keep-alive circuit to allow instant on from a standby condition. (The green wire on the output side.) Don't mess with the green wire with yellow stripe that is on the input side. That one is a safety wire for the input protection.

A WORD of CAUTION: Give your power supply a chance! Design engineers cannot anticipate and design in protection for all conditions and still give you a power supply you can afford. When you turn it off, wait 10 seconds before restarting so that capacitors can discharge and voltages can settle to stable conditions. You may never be able to make a power supply fail if you don't, but you will not be happy if you do. I have designed power supplies, purchased, and tested PC and custom power supplies. I have two bad hard drives from a system I bought from DELL last year. A friend could not tell that the system turned on (too quiet) so he pushed the power on/off too rapidly and too many times. Twenty years ago,my first computer suffered a power supply failure when I turned it off and immediately changed my mind and turned it back on.

Power supplies with phony UL certifications

[Animats]

As usual with these PC power supply tests, the supplies that passed the tests from Underwriters Laboratories work fine, and the ones that don't. In this review, there's a clear picture of each power supply label, so it's possible to check the certifications.

• The HIPER HP3S350 appears to be the first of the phonies. The label has the UL "recognized component mark" (the reversed-R U symbol), but there's no UL certification number. That's an indication of a phony; all UL marks must be accompanied by a UL certification number, an E followed by digits. Certification numbers can be easily checked with UL here.

  Looking up HIPER in the UL database, HIPER has a few products listed, but none of them are computer power supplies. So that's a brand to avoid.

• Jeantech's power supply label also has the UL component logo without a certification number. They're not in the UL database at all. Uh oh.

• The Seasonic SS 400-FB power supply has a proper UL marking, and the certification number E104405 is in the UL certification database. There's not an exact match on model; an SS-400FS was certified and this is an SS-400FB. That's sloppy, but this company is clearly trying to comply.

• SilentMax has no UL logo at all. It blew up under test. It's clear why that one doesn't have a UL certification.

• The Ultra Xconnect blew up under test. There's a UL marking, but no file number, on the label. Ultra Products has no listings in the UL database. So that's another phony.

Consistently, every power supply with a valid UL mark passed. And every power supply that blew up lacked a valid UL mark.

UL tests power supplies by loading them up to their rated load at their maximum rated temperature and running them for hours or days. They also test for safe behavior if short circuited, overloaded, or overvoltaged. They're not concerned with power quality, just safety. The device must not blow up or catch fire, even after a single component failure.

Report phony UL marks to UL at 1-877-UL-HELPS (854-3577). They arrange for seizure at U.S. Customs, and catch about $12 million a year of hazardous components, which are then crushed.