Part 1: Four Cheap 80 PLUS Bronze Power Supplies, Reviewed

[Guest]

Power supply manufacturers condition us to think that efficiency is the one variable you need to pay the most attention to. But we have a suite of tests that more thoroughly taxes PSUs. Can these four inexpensive units under $70 make it through unscathed?

Part 1: Four Cheap 80 PLUS Bronze Power Supplies, Reviewed : Read more

 

[wolley74]

no love for the EVGA 500B?

 

[computer_nugget2]

ALWAYS judge a power supply by its weight. especially if its Chinese.

 

[InvalidError]

always judge a power supply by its weight.

Some Chinese OEMs put rocks, small concrete blocks, lumps of steel or other stuff like that disguised as a transformer with bits of wire that aren't connected to anything to trick people into believing their heavier PSUs are better.

So weight alone is not a reliable indicator.

Also, at high frequencies and high efficiencies, the size of inductors, capacitors, transformers and heatsinks along with the associated weight shrink. While light weight and high quality may rarely be seen together, they certainly are not mutually exclusive.

 

[dudewitbow]

no love for the EVGA 500B?

a good chunk of Tom's physical hardware reviews generally are conducted in europe. This goes for a good handful of the gpu tests as well. EVGA rarely ever shows up on review sites because of it(and possibly due to lack of EVGA response to a hardware review pitch)

 

[computer_nugget2]

always judge a power supply by its weight.

Some Chinese OEMs put rocks, small concrete blocks, lumps of steel or other stuff like that disguised as a transformer with bits of wire that aren't connected to anything to trick people into believing their heavier PSUs are better.

So weight alone is not a reliable indicator.

Also, at high frequencies and high efficiencies, the size of inductors, capacitors, transformers and heatsinks along with the associated weight shrink. While light weight and high quality may rarely be seen together, they certainly are not mutually exclusive.

do you have pics to prove this?

 

[envy14tpe]

This is PART 1. Which means more PSUs to come, so let's hope for no dumb comments asking why not this PSU or this one...

 

[jimmysmitty]

This is PART 1. Which means more PSUs to come, so let's hope for no dumb comments asking why not this PSU or this one...

They have already listed the PSUs for part 2 and I didn't see a part 3 listed. I wonder where the Corsair CX430 is. Its a 85+ Bronze PSU and is $39.99 on Egg right now. Its one of the best entry level PSUs I have actually used as well and compared to other PSUs at the same price point or higher (within 550W and may or may not be 80+ at all) I have seen less of them come back bad.

 

[razor512]

always judge a power supply by its weight.

While weight is an important factor, overall weight is 100% useless

for example check out the SIGMA SHARK SP-635

http://www.ocia.net/reviews/sigma635/page2.shtml

it is probably one of the heaviest power supplies you will find (with the exception of some of the 1200 watt ones)

I purchased it a while back and was disappointed at the internals. they used an insanely thick case that made the power supply weigh a lot but the insides were were the result of the owner of the company asking while walking around china, what are the cheapest items we can find on the shenzhen market today.

(at least the power supply can double as a flail or a boat anchor)

 

[pyro226]

Hoping to see the CX430 and other corsairs reviewed. I like the little thing since it powers my PC. It originally rang a bit when the computer was suspended or at random after a few hours of use, but that went away with age.

 

[sanilmahambre]

Nice basic testing method

 

[benedict78]

One very important question is not answered in this article. Do any of those PSUs support the new Haswell C7 state? Anyone who's buying a new Intel 4xxx processor should know if his PSU is compatible with the CPU.

 

[PreferLinux]

Could you do a shot of the spikes using a sweep time of 1 us/div, or even less, in the next part please (assuming you get them)? And maybe one that shows a single cycle of the PWM switching (clearly defined on some of these)? It'd be really interesting – I've got some theories about what is causing it, but nothing concrete yet...

 

[butremor]

Who's Who In Power Supplies
Really useful article, let's you look for reviews of PSU real manufacturer if needed.

 

[Someone Somewhere]

How are you loading the minor rails? Loading 12V only will unfairly penalise group regulated designs, which do much better with even a little load on 5V/3V3. Systems still have some load on 5V/3V3, usually things like audio chips on the MB and HDD/SSD electronics.

I'm waiting for the XFX 550W - those go for about $55 (seems to be $62 now), and are supposedly pretty decent.

EDIT: On further reading, you've got a pair of Chroma load testers - so what are the bulbs for?

 

[Someone Somewhere]

And for the most part are very close to THD=0. Which is a resistive load.

(Hint: Capacitors and inductors balance out.)

 

[vertexx]

Why no Corsair? Seems like a pretty big omission - I'm sure there's an explanation, but it would be helpful to understand why? The Corsairs have to be one of the top selling PSUs right now due to their aggressive pricing and general perceived quality. It would be really good to know how these match up, because they are right now my "go-to" brand for budget PSUs.

 

[Someone Somewhere]

Less than, but generally rather close. Besides, capacitance actually makes them work better - smooths out ripple.

See the 'Part 1'? Probably going to be more later.

 

[InvalidError]

do you have pics to prove this?

Search for "Fake PFC transformer"

Here's a page with a bunch of examples:
http://www.pcpop.com/doc/0/294/294565_all.shtml

Granted, they are all brands almost nobody knows. Hantol isn't on the list above and seems to be the only other manufacturer who's been caught doing this.

My point simply was: it is known to have happened.

 

[InvalidError]

Resistive load has power factor of 1. DC-DC converters have power factor of less than 1.

Actually, DC-DC converters have no power factor in the conventional meaning of the term whatsoever since power factor is used to represent the discrepancy between AC voltage and current which itself is a combination of phase shift and distortion factor intended to represent how much unlike-a-resistor an AC load is.

DC-DC converters are roughly constant-power load and aside from inrush while their input and output caps get charged and load changes, they are practically indistinguishable from resistive load to the upstream AC-DC or DC-DC converter as long as it has enough local decoupling to remove most of the switching noise and ripple.

If you were to calculate the "power factor" of DC-DC converters which basically boils down to determining how much power gets transferred at 0Hz vs any power exchanged at frequencies above that since there is no phase to worry about at 0Hz, you would find out DC-DC converters are indeed very close to 1.

 

[Someone Somewhere]

Yup.

There is, however, a term called 'total harmonic distortion', which (IIRC) refers to the amount of noise produced by a device.

You can basically treat any load as resistive in DC though - the ripple is barely noticeable (<5%) vs more than twice RMS voltage for AC. And it only occurs on the ripple.

I can probably scrounge some stuff out to test it though, but it's not really necessary.

 

[vertexx]

This is PART 1. Which means more PSUs to come, so let's hope for no dumb comments asking why not this PSU or this one...

He already listed the PSU's:

In this piece, we have power supplies from Antec, Chieftec, Cougar, and Enermax. The second part will include Cooler Master, Gigabyte, OCZ, and Seasonic.

So, dumb is dumb I guess.

 

[InvalidError]

There is, however, a term called 'total harmonic distortion', which (IIRC) refers to the amount of noise produced by a device..

THD is already accounted for in the PF measurement as the "distortion factor" which accounts for all power transferred at frequencies other than the fundamental.

So on DC which has no phase error, only the distortion factor remains. What you said was implied in what I said.

 

[computer_nugget2]

do you have pics to prove this?

Search for "Fake PFC transformer"

Here's a page with a bunch of examples:
http://www.pcpop.com/doc/0/294/294565_all.shtml

Granted, they are all brands almost nobody knows. Hantol isn't on the list above and seems to be the only other manufacturer who's been caught doing this.

My point simply was: it is known to have happened.

it would help if the thing wasn't in chinese.

 

[ddpruitt]

I think Tom's needs to brush on electronics design a little for these articles. A purely resistive load (like lightbulbs) won't accurately simulate what happens inside a computer with varying inductive and a capacitive loads, especially since they change with time. It also doesn't measure the effects of electrical noise from the various components (CPUs, GPUs, Memory, etc). While the inrush current is interesting I would also like to see the first few moments of startup, something may have a low inrush current but may spike suddenly. I'm also curious on startup voltages, see how stable they are before they settle.

Great start but I think a little tweaking is required. I've always wondered how good these PSU's really are.