Choosing a computer power supply is easy, provided that you are not making the mistakes that other people are making. One of the most common mistakes people made when building their own computer is to neglect the importance of computer power supply. They tend to cut down their budget on computer power supply and get the cheapest one around. If you really care about your computer system, you have to put in some serious effort to choose the best power supply.

The computer power supply is the energy source for the whole computer system. Imagine that you are not eating well for every meal, do you think you can still function well for all your daily tasks?

Power Rating

While people are discussing about the gigabytes of storage, 64 bit processing capabilities and the heavy-duty 3D graphics card, the only thing that required the most attention, but is discussed least is the computer power supply. What they have not realized is that the more powerful a computer become, the more power it needs. If you are wondering how much power you need for your system, check out the table below:

Computer Parts	Watts
Motherboard	15-30
Low-End CPU	20-50
Mid To High-End CPU	40-100
RAM	7 per 128MB
PCI Add-In Card	5
Low To Mid-Range Graphics	20-60
High-End Graphics	60-100
IDE Hard Drive	10-30
Optical Drives	10-25

Add up the power required for your system and get the power supply with a power rating higher than the required power. If you are building a high-end gaming computer, chances are you may need a 600 - 650W power supply.

Mean Time Between Failure (MTBF)

This is also known as the lifespan of the power supply. It represents the average hours the power supply can perform before it fails. Most power supplies will have MTBF ratings of 100,000 hours or more, but be aware that these figures were not collected from actual real-time testing. Most ratings are based upon the comparative failure rates of the power supply’s individual components.

Short Circuit Protection

When choosing a computer power supply, make sure that it is equipped with a short circuit protection feature. This is to prevent the computer parts from drawing excessive currents which might cause its internal chips to be burned.

Low Noise

The main reason for a power supply to be noisy is because of its inability to dissipate heat fast. The fan has to work extra hard to maintain the required temperature. When choosing a computer power supply, make sure that it comes with a big powerful 140mm fan or two 80mm fans to effectively dissipate the heat away.

Load Current (Maximum and Minimum values)

Each computer part requires different voltage and current to function. It is important that the power supply can support the various voltage levels and the current supplied.

Maximum load current - Tthe maximum current that the computer part can accept for a particular voltage level

Minimum load current - The minimum current the computer part needs to be functional.

If the part is not getting the minimum load current from the power supply, chances are the power supply is spoiled.

Form Factor

Most of the power supplies in the market are of the ATX form factor. However if you are using a micro ATX computer case, you have to get a micro ATX power supply, else it won’t be able to fit inside the case.

Conclusion

Power supply is definitely a computer part that you must pay attention to. When choosing a computer power supply, always get a power supply that has a higher power rating than what your system needs. In addition, unless you are willing to risk your computer to system jeopardizing power spikes and surges, don’t ever scrimp on the power supply.