What are the differences between bronze through platinum power efficiency on power supply's.?

Answer 1

The 80+ certification ensures that the power supplies you're buying achieves at least 80% efficiency from power draw (out from the outlet) to what your computer actually gets.

The Bronze to Platinum and Titanium ratings up the minimum requirements from as high as 85 to 90% efficiencies.

Answer 2

It is the 80 Plus certification levels about which you are inquiring. As you know, there are several different levels that have to do with the efficiency of the power supply at ten percent, 20 percent, 50 percent load, and full load. This is rated on both 115-volt and 230-volt systems.

For the specific requirements, they are as follow:

80 Plus at 115 volts must be at least 80 percent efficient at 20, 50, and 100 percent loads and efficiency at 10 percent is not defined. There is no definition for basic 80 Plus certification in the 230-volt systems.

80 Plus Bronze at 115 volts must be at least 82 percent efficient at both 20 percent and 100 percent loads but also at least 85 percent efficient at 50 percent load. The numbers are nearly the same for 230-volt systems: the 20 and 100 percent loads must be 81 percent efficient rather than 82. Once again, there is no definition for ten percent load under either voltage.

80 Plus Silver at 115 volts must be at least 85 percent efficient at 20 and 100 percent loads and 88 percent efficient at 50 percent load. 230 once again is nearly the same with the only difference being slightly higher efficiency required at 50 percent load: 89 percent instead of 88. No definition for 10 percent load for either voltage.

80 Plus Gold at 115 volts must be at least 87 percent efficient at 20 and 100 percent loads and at least 90 percent efficient at 50 percent load. Under 230 volts, all the numbers are a bit higher: 88 percent at 20 and 100 percent and 92 percent at 50 percent load.

80 Plus Platinum at 115 volts must be at least 90 percent efficient at 20 percent load, 92 percent at 50 percent load, and 89 percent at 100 percent load. In a 230-volt system, the percentages are 90 percent efficient at 20 percent load, 94 percent at 50 percent load, and 91 percent at 100 percent load. Once more, no definition for 10 percent load under either voltage.

Finally, 80 Plus Titanium at 115 volts--which is the only one that defines efficiency at 10 percent load--must be at least 90 percent efficient at 10 percent load, 92 percent at 20 percent load, 94 percent at 50 percent load, and 90 percent again at 100 percent load. At 230 volts of system power, it must be at least 90 percent efficient at 10 percent load, 94 percent at 20 percent load, 96 percent at 50 percent load, and 91 percent at 100 percent load.

Now if you want to understand what this means, it is referring to the amount of wall power that is converted into usable power for the computer. To help illustrate this, let's consider a common, non-80Plus-certified power supply that is only about 60 percent efficient. If it is to supply 450 watts of power to the computer, then that would mean that it would pull 750 watts of power from the electrical service. (750 x 0.60 = 450, of course.) In other words, 300 watts of power would be wasted to heat and other byproducts of the conversion from 115 (or 230) volts of AC current to the various voltages of DC current provided by the power supply. In contrast, a power supply with a basic 80 Plus certification would use only 562.5 watts from the wall to produce those same 450 watts of usable power. Considering that power is based on what is consumed from the wall, that would save 187.5 watts per hour. If one leaves the computer on for a full 24 hours, that would lead to a savings of 4500 watts, or 4.5KW. Monetarily, this leads to a savings of about 59 cents for that single day of use. Presuming that the computer is left on 24 hours a day for the entire month, the efficiency of the basic 80 Plus certification would lower the electric bill by nearly $18. Savings would be even higher with the higher certification standards.

When one looks at the prices of 80 Plus-certified power supplies (especially those at higher certification levels), one may think they are not worth it because of the great investment. However, as is demonstrated in the above paragraph, they easily pay for themselves in a short time by the money saved on the power bill. Thus, I recommend having 80 Plus power supplies in any computer you own.