How Power Supplies Are Rated

[shirleydeng]

Still very useful to me, thanks for poster.

 

[GeoBut]

Why is it important to buy a power supply that's close to the requirement for your system instead of buyng a higher wattage power supply?

 

[theAnimal]

Originally posted by: GeoBut
Why is it important to buy a power supply that's close to the requirement for your system instead of buyng a higher wattage power supply?

It's best to buy a power supply that will be between 30-70% loaded for optimal efficiency.

 

[HOOfan 1]

as long as you buy a high quality power supply, buying a PSU that is much higher than you need is perfectly fine as well. Efficiency may not be as high, but it won't do any harm

 

[theAnimal]

Bump for re-sticky.

 

[Tech_savy]

Very Informative but was wondering what MTBF is....

 

[theAnimal]

Very Informative but was wondering what MTBF is....

Mean Time Between Failure

 

[crat3rs]

Power rating

Computer power supplies are rated based on their maximum output power. Typical power ranges are from 300 W to 500 W lower than 300 W for Small form factor systems and are intended for ordinary home computers, the use of which is limited to Internet-surfing and burning and playing DVDs. Power supplies used by gamers and enthusiasts mostly range from 450 W to 1400 W. Typical gaming PCs feature power supplies in the range of 500-800 W, with higher-end PCs demanding 800-1400 W supplies. The highest-end units are up to 2 kW strong and are intended mainly for servers and, to a lesser degree, extreme performance computers with multiple processors, several hard disks and multiple graphics cards. The power rating of a PC power supply is not officially certified and is self-claimed by each manufacturer. Power Supply Fundamentalsr How PSU Power Ratings Mean Almost Nothing A common way to reach the power figure for PC PSUs is by adding the power available on each rail, which will not give a true power figure. Therefore it is possible to overload a PSU on one rail without having to use the maximum rated power.
Sometimes manufacturers inflate their power ratings, in order to gain an advantage in the market. This can be done due to a lack of clear standards regarding power supply labeling and testing.

• Advertising the peak power, rather than the continuous power;
• Determining the continuous output power capability at unrealistically low temperatures (at room temperature as opposed to 40°C, a more likely temperature inside a PC case);
• Advertising total power as a measure of capacity, when modern systems are almost totally reliant on the current available from the 12 volt line(s).

This may mean that if:

• PSU A has a peak rating of 550 watts at 25°C, with 25 amps (300 W) on the 12 volt line, and
• PSU B has a continuous rating of 450 watts at 40°C, with 33 amps (400 W) on the 12 volt line,

and those ratings are accurate, then PSU B would have to be considered a vastly superior unit, despite its lower overall power rating. PSU A may only be capable of delivering a fraction of its rated power under real world conditions.
This tendency has led in turn to greatly overspecified power supply recommendations, and a shortage of high-quality power supplies with reasonable capacities. Very few computers require more than 300–350 watts maximum.[1] Higher end computers such as servers and gaming machines with multiple high power GPUs are among the few exceptions.

- excerpt from http://en.wikipedia.org/wiki/Power_supply_unit_(computer)

 

[slayernine]

The ability to handle different voltages without a switch can prove very useful. While at a large LAN party here in Canada called Fragapalooza one row of computers was accidentally switched to 240v from 120v. Nobody noticed until one computer started smoking. That computer was the only one with the little 120v/240v switch on the back. All the other guys playing games switched over seamlessly.

 

[stefan12]

Just because it uses the same platform does not mean the PSU is rebadged!

you are just right

 

[LiuKangBakinPie]

No rebadging was done!!
The definition of the word "rebadge' when it concerns PSU`s mean that the PSU that you say is rebadged uses exactly the same components and looks exactly the same as a PSU that has a different companys label.

Just because it uses the same platform does not mean the PSU is rebadged!

A good example of a rebadged PSU would be if you bought say brand A and then brand B....
You took them both apart and they used exactly the same componemts and caps and heatsinks they looked exactly the same. mThat is 'rebadging".

Sentey Gold steel 850w/NZXT hALE 90 850W

 

[LiuKangBakinPie]

The ability to handle different voltages without a switch can prove very useful. While at a large LAN party here in Canada called Fragapalooza one row of computers was accidentally switched to 240v from 120v. Nobody noticed until one computer started smoking. That computer was the only one with the little 120v/240v switch on the back. All the other guys playing games switched over seamlessly.

doesnt smoke they go poof with a blue flame normally appearing. If the unit was junk then it takes the onboard graphics normally with it. But pc still work