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What makes a GOOD PSU good?

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a b B Homebuilt system
January 23, 2008 11:42:28 PM

My question is what exactly makes a good quality PSU good quality? What are the differences in the quality (ie tier 1 vs tier 3)? Also If I just get a cheap PSU and replace most/all of the parts such as the capacitors, etc with high quality ones (ie solid caps) will it make it a difference?

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a b B Homebuilt system
January 24, 2008 12:14:13 AM

What makes a good quality PSU good is that it is better bad quality PSU and that it lasts longer.

A PSU that lasts a long time is a GOOD thing
A PSU that lasts a short time is a BAD thing.

Tier 1 is good quality
Tier 3 is not good quality

Expensive parts are better than cheap parts.

Good capacitors are always better than bad capacitors.

Solid capacitors are always solid, which means they are full. Which means you get more for your money than an empty capacitor which looks identical to a solid capacitor from the outside.

A good quality PSU will definitely make a difference over a bad quality PSU.

A Good PSU means that it is desirable and you should want it.
A Bad PSU means it is not good or desirable and you should not want it.
January 24, 2008 12:54:50 AM

What makes a good PSU? What makes good Chinese? The answers to these questions are pretty similar:
Quality parts/ingredients.

Edit:
Quote:
Solid capacitors are always solid, which means they are full. Which means you get more for your money than an empty capacitor which looks identical to a solid capacitor from the outside.

I hope that was a joke...
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January 24, 2008 1:16:23 AM

You might as well buy a higher quality power supply and save yourself the hassle if you are replacing capacitors.
January 24, 2008 1:21:48 AM

Shadow703793 said:
My question is what exactly makes a good quality PSU good quality? What are the differences in the quality (ie tier 1 vs tier 3)? Also If I just get a cheap PSU and replace most/all of the parts such as the capacitors, etc with high quality ones (ie solid caps) will it make it a difference?


You wouldn't really want to mess around inside a PSU for one thing, also, cheap ones will have lower quality internals other then capacitors, not to mention a probably shoddy heatsink arrangement. The cost of time and effort for changing out the capacitors yourself is most likely going to outweigh any cost savings with a cheap power supply anyway. Your best bet is to just pony up the cash for a decent power supply.

Note: quality power-supplies will also have stuff like active-PFC, over-voltage protection and better quality cabling.
January 24, 2008 1:31:27 AM

Shadow703793 said:
Also If I just get a cheap PSU and replace most/all of the parts such as the capacitors, etc with high quality ones (ie solid caps) will it make it a difference?
That's a laugh... no wait, that's ridiculous. It's not just the components that are better, in many cases it is also the design. See www.jonnyguru.com for additional information.

Stop trying to get over somehow and just buy a decent PSU. By the way, tier 3 are passable just not preferred. A tier 2 is good and there are some that aren't too expensive.

Think of it as insurance against the cost and aggravation of repairing other components damaged by a PSU that blows up. Additionally, just because you get a tier 1 or tier 2 PSU doesn't guaranty that it won't blow up, it just significantly reduces the chances.
January 24, 2008 6:53:19 AM

If you buy a cheap PSU and replace all the Parts then wouldn't you be spending the same or more Money in the end than if You'd just got the good one instead?

And Grave makes an exellent point. It's not only good parts but support Circuits as well i.e. ripple and phase filtering.
Another thing has to do with the quality of the Transformer as well i.e. Cheap Transformers have a low Q factor as higher quality Transformers have much higher Q factors. This makes a big difference in the ratio of input to output current.
A cheap PSU will take 800-1,000W out of the Wall to make 600W, a good PSU will only take 650-680W to make the same 600W.

There's allot more to a high quality PSU than Capacitors...
a b B Homebuilt system
January 24, 2008 11:09:20 PM

^No getting the solid caps will cost you about $11 for the entire PSU.

Thanks for the link Zorg. Btw, I strongly believe in getting a good PSU, but this was an idea that I just had and wanted to see what others thought.
January 25, 2008 5:36:48 AM

Replacing the caps in an old PSU where they are failing is not a bad idea if you are short on cash, but you should just buy a decent PSU to start with. Not to mention that you will void any warranty as soon as you open the case. You can usually find a decent PSU on sale for a little more than a cheap one.

I don't know what your specs are, but if your system isn't too power hungry the Antec earthwatts EA500 is a decent PSU built by Seasonic and is only $49.99 after $30.00 Mail-In Rebate.

Even cheaper is the Antec earthwatts EA430 for $24.99 after $30.00 Mail-In Rebate. A decent PSU for a junk PSU price. $11 for caps means you would have to get your PSU for $14 and I don't think that's going to happen.

You can determine your recommended PSU size with the eXtreme Power Supply Calculator v2.5. Make sure you read the foot notes to ensure that you input the spec data correctly.
January 25, 2008 8:01:34 AM

"heavy is good, its a sign of reliability" (C) Boris the Blade aka Boris the Bulletdodger.
a b B Homebuilt system
January 25, 2008 8:33:18 AM

Another difference in quality is testing. Cheap PSU's often just get a simple Hi-pot load test. If they do not catch fire, they get shipped. They do not get tested for ripple effect, or voltage drop off, etc... This assumes they get tested at all. Many low cost suppliers simply do batch testing, as opposed to every unit.

Another feature of cheap PSUs is that you may buy a 500w, but it may actually be a 300w inside. If you are running a low end Celeron system with integrated video, you might be just fine.

The heavy comment above also applies to quality. Quality coils and heatsinks are heavy, as are quality capacitors.

The biggest problem with cheap PSU's is that when they fail, they will usually take the rest of your components with them. This failure is usually due to poor quality voltage regulators(the things that can cause fires). In other words, you will have a very decorative doorstop instead of a computer, not to mention the awful stench of burning silicon.

You could certainly replace the components as long as you replace each and every one with quality. Price that out and see how it works for you. :) 
a b B Homebuilt system
January 25, 2008 9:49:57 PM

@Zorg: I have a good PSU (a corsair 520HX) the replacing caps, etc was just an idea that I had for my old (not really since its only 3months old) Logysis 480W and use it to power just my HDDs, DVD drives, and fans.
January 26, 2008 1:57:48 PM

Oh, well that's not what you said. Depending on the load on your HX I wouldn't use it unless you had to. But replacing the caps on a an old/cheap PSU is not a bad idea. The caps aren't the only thing that makes a cheap PSU bad. You could have perfect caps and a bad/cheap regulator design etc. and still get dirty power. Read some of jonnyguru's PSU reviews, some PSUs are just crap. Bad PSUs can eat parts especially HDs even though they haven't "blown up".
a b B Homebuilt system
January 26, 2008 3:35:29 PM

^Thanks. Mind linking me to some detailed info on PSU designing, etc.?
a b B Homebuilt system
January 26, 2008 6:32:59 PM

Thanks Zorg.
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