# 80 bronze vs 80 gold

How to choose between a 80+ bronze and a 80+ gold power supply?

1. Calculate approximately how many hours you are using you computer per week
2. Find how much a kWh costs at your area
3. Use the tables below to find how many weeks it would take an 80+ Gold power supply to pay for the cost difference over an 80+ Bronze power supply

Here are some examples:

##### Example 1:

Let’s say you are using a 450W power supply and each kWh costs you \$0.1. You are using your computer approximately 8h per day (56h per week).

It will take approximately 333 weeks (6.5 years) for the 80+ Gold power supply to pay for the cost difference over an 80+ Bronze power supply.

##### Example 2:

Let’s say you are using a 450W power supply and each kWh costs you \$0.1. You are using your computer approximately 24h per day (168h per week).

It will take approximately 111 weeks (2.15 years) for the 80+ Gold power supply to pay for the cost difference over an 80+ Bronze power supply.

So, should you always prefer bronze over gold?

The answer is NO. You have to taken into account some other factors like:

1. More efficient power supplies emit less heat. As a result they produce less noise. If you are interested in building a silent PC a more efficient (and expensive) power supply may be what you need.
2. Assuming we are comparing two models of the same manufacturer, more efficient power supplies tend to have components of higher quality. Which makes them a better choice for your expensive (?) computer.

References: