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How To Choose A Power Supply?

by Linda D. Yelverton

The power supply unit or PSU might be the most critical component in the computer. This can influence the overall performance in so many ways. But have you noticed that there are so many options out there? There are also all the big terms associated with the power supply configuration like ‘80Plus Rating’, ‘wattage’ and lots more. Do you feel daunted to even look at the specifications? Do not worry, here is a guide that will get to the very basics to help you choose a suitable power supply unit for your computer. This will be a great place to start when you wish to study about computer power supplies. You would be able to choose one that is worth the expense.

So what are the requisites to picking a good power supply unit?

Outlet for power supply

  1. All about 80Plus rating

It is the parameter that talks about the efficiency of the power supply. This is therefore the most important consideration.

There is a 230V certification for redundant units and 115V for non-redundant units. For industrial applications the 115V units are still in the picture as the 230V units did not bring about a drastic improvement in the efficiency.

Efficiency is the percentage that is derived by comparing the power output from the power supply unit against the power that it draws. If it delivers a number close to the input power wattage then it is said to be more efficient. When the difference is huge the extra power is often eliminated in the form of heat energy. Based on the efficiency levels the popular ratings are –

  • 80Plus
  • 80Plus Bronze
  • 80Plus Silver
  • 80Plus Gold
  • 80Plus Platinum
  • 80Plus Titanium

The 80Plus Gold rating is often considered an optimal choice for reliable performance computers when you cannot stretch your budget too much.

  1. Wattage and its weightage

This is often the first parameter that you might study when you buy PSU. This talks about the actual output power delivered by the PSU. You should first study the total wattage requirement of the hardware in your computer. This also depends on the type of computer you build. For gaming computer, the hardware configuration might demand a higher wattage. In most of the cases you would be able to find the wattage requirement furnished as a specification with the hardware component you buy. This makes it easy to choose the right output power supply unit. Depending on the input power drawn and the efficiency rating the output power fluctuates. Most power supplies are designed to lower the output in a way that reduces the heat dissipated. Therefore keep the clearance in mind when you choose the required wattage.

  1. The external aspects

The external aspects of a PSU include the aesthetics of it like the rails and the ports that it packs. Multi-rail systems and single rail systems are both used in different places as they have their own pros and cons. If the focus is on even power distribution to all internal components a single rail design does the job well. But if surge protection is of prime importance then a multi-rail system would often be a better choice.

Choose the right sized PSU. It should definitely not take up too much space within your computer. Remember that you might be integrating a cooling fan and also allow some space around the unit for air circulation to help to cool the unit down.

If you are building a circuit from scratch then you can work around a PSU and find suitable components. When you are buying a PSU for your computer you would have to check the type of ports required based on the connectors that the components accept. Begin with the GPU requirements and the serial ports. This can help you pick the total number of ports required.

Once you have the information, here are a few quick tips to pick a suitable PSU


Do not stick with the wattage number alone. Of course, you should use this as an attribute to find the segment where you should look for the PSU. But the wattage is of no meaning if you do not compare it with the efficiency. Therefore jot down the wattage requirements of the components in your computer.

Pick a wattage value well above this requirement. Then pick a high-efficiency PSU one with 80Plus Gold rating or more. Gamers might even find the Platinum rating to be a better choice. If you need a dependable computer that doesn’t heat up for heavy tasks, a Gold rating should suffice. Sort your options based on the pricing and stick with a reliable name in the industry.

The quality of the PSU matters as much as all the above factors. Quality here refers to the hardware quality in general and the reliability of the ports and connectors. Choose a suitable profile based on your computer case style. This ensures that you can install the unit in the existing hood without having to further extend your budget or modify the shell. You should not buy something that sits in a cramped up space. This is not just bad for the PSU but also for the other components inside. Air circulation to the other components should also not be hindered by the power supply unit you choose. Compact, powerful and reliable power supply units for all types of computers are available in the market today.

Wrapping it up

Hope we managed to clear a few questions you might have had on your mind. We also hope that the next time you set out to buy a power supply unit you would not feel overwhelmed with the choices available. Know the popular brands you can rely on as a beginner. Shortlist based on your requirements and then pick one that meets your budget. Whether you plan to perk up your computer or tackle heating issues or even build a computer from scratch these fundamentals can be of great help. Back it up with your research about the power supply unit cooling options.

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