Reasons you should Avoid Buying a Computer Power Supply with Poor Efficiency

I bet you have heard it many times that you should never buy or use a Computer Power Supply that has poor efficiency. But why is that so? Well, I guess you want to know the reasons and that’s why you are here. Just read on to learn more.

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A power supply is meant to convert the current from the power outlet (AC) to DC or what the parts of your computer use. Since this is not actually a perfect process, there are some amounts of energy that get lost in the form of heat during the process. On average, Desktop Power Supply efficiency can generally be as high as more than 92 percent or as low as 60 percent.

The negative impacts of a power supply with very poor efficiency

The main reason you should avoid a power supply with poor energy efficiency is that it will make your electricity bill to explode. To help you understand what we mean, we can do some calculation here to compare an 85 percent efficient power supply and a 70 percent efficient one. Actually, these are the two efficiency level that you will commonly find in computer power suppliers including those that we are selling at

Let us assume that you have a Dell computer which consumes about 500 watts on average when you use it for 10 hours every day and your electricity cost is $0.15 per KW per hour. A Dell Power Supply with an efficiency of 70 percent will be using approximately 710 watts to output 500 watts. On the other hand, a Dell Power Supply with efficiency of 85 percent will use approximately 590 watts to output 500 watts. This is a different of 120 watts between 855 and 70% efficiency.

Mathematically speaking, 120 watts x 10 hours will be 120 watts per day. In a year, it will be 120 watts per day x 365 days, which will be 438,000 watts more yearly. Precisely, your electricity bill in KW will be 438,000/1000, which will be 438 KW. If you multiply the total KW with the total cost of KW/H, i.e. KW/H 438 x $.0.15, you will find that you will be paying $65.70.

That is exactly the difference in the cost the electricity bill for a year. You can now imagine how much more money you will be paying in 10 year. So, whenever you are buying a power supply, be it a Lenovo Power Supply, Desktop Power Supply, or HP Power Supply, you should always insist on picking the unit with 80% efficiency. is professional power supply trading and power supply wholesale provider, mainly focused on dell,hp,lenovo / IBM power supply and server workstation components.