Power supply numbers

[kenmo]

I realize Corsair is one of the better power supply companies but that aside can someone kindly what these figures mean...

(see attached jpegs)

Now based upon these figures, (name of manufacturer aside) which power supply has the better power numbers and why?

Thanks kindly...

[jagabo]

You can't believe anything a poor manufacturer claims about their power supplies.

http://www.anandtech.com/show/3985/three-550w-psus-for-different-prices

A respectable manufacture would call that Logisys PSU a 330w PSU, not 480w. And even as a 330w PSU it's cheaply built and likely to fail at any time.

Don't skimp on your PSU. When it fails it can fry many other components in your computer.

[kenmo]

Then should the Corsair really be called a 396w ps? I really don't understand the numbers....

[jagabo]

Then should the Corsair really be called a 396w ps? I really don't understand the numbers....

No. The 396W is for the 12V output only. 480W (below it) is the sum of all the outputs. And it should be able to sustain that indefinitely (in reality many power supplies will fail before that point, or some of the voltages will fall below spec). The Logisys shows a combined total of 330W. Their 480W number means something like it can put out 480 watts for a microsecond or two, but if you go longer than that the thing will fry.

A PC power supply outputs several voltages: 3.3, +5, +12, -12, and +5 (standby). On the Corsair PSU you can see them listed in one row labeled DC Output. Below each of those is the maximum amps that can drawn at each of those voltages. For example 33A at 12V. For DC circuits Watts = Amps * Volts. So 33A * 12V = 396W. But that's just for the 12V output.

Some of the circuitry is shared between the different outputs. So you can draw the maximim of each output from all the outputs at the same time. 480 watts is the maximum combined output. So if your computer was to draw 396W from the 12V line there would only be 54W left for the other lines.

[kenmo]

But what I don't understand how do you read all of those numbers... How can they compare to each other?


ie:
+3.3v 0.3A 28A +3.3V & + 5V= 200W
etc...

I would like to read & understand these figures so when I'm shopping for a power supply at Newegg or Amazon I can decide what is a good power supply...

Are there any links to how to read these figures (and please NO links to power supply reviews..)...

Thanks kindly...

[jagabo]

I added some text to my previous post.

You need to make sure that you don't draw more than the indicated max at each of the voltages, and that the total amount you draw doesn't exceed the stated maximum. It's usually difficult to figure out how much power you need at each voltage. It's easiest just to buy a beefy power supply and be safe. TomsHardware or AnandTech did an article about that a year or so ago. They went through several common computer setups and determined how much power was needed at each voltage. Then looked at typical power supplies and suggested what was appropriate.

I think this is it: http://www.anandtech.com/show/2624

By the way, there are online PSU calculators around. You enter the parts you plan to use and they'll tell you what you need. For example:

http://www.antec.outervision.com/

[TooLFooL]

that's the minimum and maximum current it can supply at the various given voltages. the first column marked 'load' lists the different voltages this brick can supply. it doesn't just make one voltage (ie. +12v) it produces six different voltages, and can provide a certain amount of current for each one. you really need an understanding of electricity and electronics to understand what these numbers mean.

but to sum it up for you... these numbers are crappy and so is corsair!

[kenmo]

I thought Corsair along with Enermax, Antec, Seasonic, Forton & Sparkle were the best? Am I wrong?

Thanks kindly

[TooLFooL]

Antec is the only one of that bunch i'd personally buy...

it seems you are trying to find the cheapest power supply that meets your requirements? i mean, corsair makes some nice units, but they're $150.. if you want a good, cheap PS i myself trust antec. i dunno how much you want to spend tho? how important is the rest of the computer to you? how much noise can you tolerate? i have an antec 850 quatro.. it cost $125, its very quiet, and easily provides twice as much current as i will ever use - but it determines the fate of another $1000+ worth of components plugged into it... now's not the time to be cheap!

[DarrellS]

My Antec lasted a couple of months. I've had the Corsair for over a year with no issues. I'll never buy another Antec. My brother and his son both bought Thermaltake's. I like the idea of plugging in only the cables that you need on the Thermaltake.

I can't afford to spend $200+ on a PSU but I've given up buying cheap PSUs. The Antec wasn't that cheap which is why I was so pissed when it failed so soon. I probably paid $120 for the Corsair on sale and the two Thermaltakes were around $110 on sale.

[redwudz]

I might have missed it in the other posts, but wattage = voltage X amperage. Pretty simple. On the AC line side of the PS, most all my PSs use about 130 - 150 Watts @ 120 Volts AC. My servers with about 9 HDDs each and four fans, use about 140W. My other PCs use about 130W. The servers have power supplies that run from 430W to 500W. All those PSs run cool and fairly quiet. The highest power PS I have is 500W. Much above that is just a waste of money, IMO. If you have a dual SLI card setup, then you might need more power.

I quit buying Antec when the last one was really noisy and it turned out the fan leads were rubbing the fan blades. So much for quality control. I still use the PS after a repair, but I don't trust them any more. I prefer Thermaltake at present and they have worked really well and are very quiet, especially the models with a 140mm fans. I do have a Cooler Master, Corsiar and a couple of other brands. No problems with any of them. But none of them were a cheap brand.

Years ago I had a computer case with a cheap 400W PS. When it died, it shot sparks out the back and fried everything in the computer. The floppy survived, but everything else was toast. It was lucky it didn't start a fire. That cost me about $400US to replace the PC internals and the cheap PS probably cost $20. Not such a good deal and no more cheap PSs for me.

One fairly basic way to get an idea of the quality of the PS is to check how much it weighs. Cheap PSs are about half the weight of good brands. Cheap PSs also run hotter and require more air to keep cool, hence more noise. Newer PSs are very efficient and with a large diameter fan, they should be very quiet.

If you have some time, wait for one of the name brand PSs to go on sale. NewEgg, Directron, Tiger Direct and even Best Buy or Frys have sales or rebates on PSs every few weeks and you can get a good deal. I'm sure in Canada you have similar computer part suppliers.

[kenmo]

Not in the market for a power supply (I have 4 computers plus one spare) and I was just curious if the existing power supplies were adequate...

Enermax 460
Corsair 550
Best Power 500
OCZ 500

Spare has a generic 450

Cheers