PSUs - Quality or Fisher Price?

[AndreiD]

The PSU is one of the most important (if not, the most important) component in your PC. Even so, a lot of buyers consider it as being a low priority when it comes to building a computer system or buying one.

 

What does a PSU (Power Supply Unit) do?

A PSU, as the name states it, supplies your system with continuous power (DC). Seems like a simple task, but is it?

 

What should you look for in a PSU?

1) First and foremost, the voltages of the +5V and +3.3V rails should be within the 5% standard and the voltage of the +12V rail(s) should be within the 10% standard when the PSU is at peak load.

2) Secondly, the PSU should have a high efficiency rating. The efficiency of a PSU shows you just how much current (AC) it can convert to (DC) current for your components.

Example: A PSU with 80% efficiency when stressed to 500W will draw in 625W from your socket. That's a 125W wasted just because your power supply isn't efficient enough.

A highly efficient PSU has two main advantages, it helps you save some dollars on your electric bill (because you are wasting less power) and it's also silent (more efficient means less dissipated heat, which in the end means a lower rpm fan).

Now most PSU manufacturers conform themselves to the 80 Plus standard. If you want to see the 80+ certified PSUs, click here.

What does 80 Plus mean? The PSU is capable of at least 80% efficiency under 20%,50% and 100% load with a PFC (Power Factor Corrector) higher than 0.9.

3) And last but not least, a PSU has to be silent (generally, it is one of the noisiest components in your PC). A silent PSU has a good fan and like I stated above, high efficiency.

 

How much power does my computer really need?

Generally, less than you think. A good 400 to 500 W PSU can easily cope with one of today's mainstream computers (a dual core with a mainstream graphic card like a GTX260 or HD5770 / HD4870 can be easily fed by a 500W PSU).

Here's a calculator which can help you determine how much your computer really needs if you want to build a new system: click.

 

Should I get a Quality Brand PSU or a Wallmart Deluxe one?

A big mistake people make is when they buy cheap PSUs (which are probably made on a fishing boat in the Chinese Sea).

Why wouldn't a 30$ 600W PSU be just as good as a 130$ 600W PSU?

- most really cheap PSUs have a hard time even reaching 60% of their stated power

- they have very bad "ripple" (voltages on the PSU rails fluctuate a lot) which may damage your other components

- they might not be very silent

- really bad efficiency rating (some really cheap PSUs can have an efficiency rating as low as 60%)

- lack any protection (I don't know about you, but I think it really sucks when a PSU dies and in a heroic last gesture, "kills" some other components with it)

To check out just how "good" some bargain PSUs are, click here.

 

A 1000W PSU consumes more current than a 500W one!

Partially false. A PSU supplies just the power your computer needs. If you're playing a video game, your components are being stressed so your computer might consume (let's say) 400 W. When posting on a forum or listen to some music, most of your components are idle or being mildly stressed, which means that your computer will require a lot less power.

What matters when comparing a 1000W PSU with a 500W one (or higher Wattage PSU with a lower Wattage one) is the efficiency rating they have. For example, a really good 1000W PSU can have a 85% efficiency when supplying 200W, which means you waste about 35W while a 500W PSU can have 80% efficiency when supplying 200W, which means you waste 50W, or it can be the other way around.

 

 

What PSU should I buy?

There are very good brands like Seasonic or very dodgy ones like Rosewill. Most manufacturers have hit or miss models. Just to be safe, when searching for a PSU to buy, I suggest you read a review about it first.

Here are some websites with really good PSU reviews:

http://www.jonnyguru.com/modules.php?name=NDReviews

http://www.silentpcreview.com/section10.html

http://www.hardwaresecrets.com/page/power

http://www.xbitlabs.com/articles/cases/

 

 

The brands I'd recommend are:

Seasonic

Corsair

XFX

Enermax

Antec (the new ones)

 

In the end, you should think of the PSU as the heart of the system. If you needed a heart, would you buy a 30$ one or would you get the 100$ one?

[Metal]

Thanks for this, a great read

[`Pepper.]

Here are the only low cost power supplys I will buy. I have used all, and I am still using the cooler masters.

 

 

(from newegg.ca, go to .com for american pricing)

 

http://www.newegg.ca/Product/Product.aspx?Item=N82E16817171028

http://www.newegg.ca/Product/Product.aspx?Item=N82E16817171046

[AndreiD]

The Cooler Masters are pretty bad;

http://www.hardwaresecrets.com/article/969/9

"Although some can see Cooler Master eXtreme Power Plus 550 W as an option if you are not going to pull 550 W from it, we can't recommend this unit, as it burns if you try to pull its rated wattage. Its main technical problem is efficiency, between 73.2% and 77.5%, which would prevent us from recommending this unit even if it could deliver its labeled power."

 

Fortron have hit and miss PSUs, but the really cheap ones are quite decent.

The Fortron BlueStorm line is also quite good for the price.

 

But seriously, why gamble 30$ with a PSU when you can get a good Seasonic/Corsair or Fortron Bluestorm II for about 60 to 70$?

[Labarr]

great read AndreiD! Currentl I got the Corsair 750Watt PSU. I purchased it because I was upgrading my video card, and it is so god damn good. Its clean, quiet, and efficient.

 

+rep for you

[AndreiD]

Corsair has Channel Well Tech or Sea Sonic inside. Very good PSUs.

[Red]

Yeah, I had some other shit brand before and it burned out on me, I spent a bit more and got a corsair this time, quieter and so far no problems.

 

*knocks on wood*

[Shadowex3]

0_o I was expecting to have to beat you over the head with Jonnyguru but you've actually just said basically everything I do. It's a strange feeling reading about powersupplies and not wanting to bang my head on the desk. I still think the best example of why not to buy a cheap PSU is actually his review of an Allied branded PSU that literally blew up when it was stress tested though.

 

Also did Antec switch back to Seasonic as their OEM or are they still selling noname power supplies and riding on their former reputation?

[AndreiD]

Antec switched to Sea Sonic with their new PSUs.

Pretty much all of their new PSUs are rock solid right now, gone are the days of the dodgy Antecs.

[`Pepper.]

The Cooler Masters are pretty bad;

http://www.hardwaresecrets.com/article/969/9

"Although some can see Cooler Master eXtreme Power Plus 550 W as an option if you are not going to pull 550 W from it, we can't recommend this unit, as it burns if you try to pull its rated wattage. Its main technical problem is efficiency, between 73.2% and 77.5%, which would prevent us from recommending this unit even if it could deliver its labeled power."

 

Fortron have hit and miss PSUs, but the really cheap ones are quite decent.

The Fortron BlueStorm line is also quite good for the price.

 

But seriously, why gamble 30$ with a PSU when you can get a good Seasonic/Corsair or Fortron Bluestorm II for about 60 to 70$?

 

For gaming computers, or anything with high power needs, then yes get a better power supply, but for a dual core, 1-2 hard drives, 1-2 disk drives, and a video card (probably up to 4850) those are good power supplies. If you plan to get a quad core eventually, then get something better.

 

http://www.10stripe.com/featured/psu/brand.php