PSU: Power Supply University, Does Your PSU Make the Grade? - Power Supply Efficiency
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In a perfect world power supplies would have a 100% efficiency rating for producing the same output as it takes in. However, our world is imperfect. The transformation of alternating current to direct current also creates a byproduct in the form of heat. This heat reduces the output of the power supply to between 65% and 85% of its intake. This heat is an unavoidable byproduct of the conversion and this is where the 80 mm fan comes into play, in dispersing it externally.
The power supply often comes with a variety of specifications to help determine its abilities. One of the most important specifications is its MTBF (mean time between failure). This specification is used to determine the power supplies projected life span, the keyword being projected. This projection is usually around 80,000 to 300,000 hours of activity, but it is not based on actually running the power supply for that amount of time. It is an estimate based on the lifespan and failure rate of individual components used in the construction of the PSU.
Another important specification is the overvoltage protection. This is the way that your PSU protects your sensitive electronic components from fluctuations and increases in the alternating current coming to your computer. This means that, should your lights flicker or the power in your home or business suddenly spike, the PSU should halt the additional voltage from entering your computer. Naturally, relying on the PSU to prevent all electrical damage from power spikes to your computer is short-sighted, and a decent surge protector should be utilized regardless of the overvoltage protection that even the best power supplies provide.
When looking to purchase a power supply for your custom rig there are a number of factors to consider. Most importantly, determine how much power all your components need. Nearly all devices have in their specifications the amount of power it needs. However, it’s not always easy to determine this. Most products have very limited or minimal details available to analyze in their specs. Thankfully, there is a mathematical method to determine exact power consumption information for most devices.
Next: Finding Out What Wattage You Need >>
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