If you have arrived at this step, then your build is almost complete. The power supply is one of the last components you will need to choose in order to complete your computer. From here on, you will only have to choose a few accessories and you are ready to mount it. I left the power supply unit (PSU) last, because it has to be chosen with care. For your computer to work, you need to choose the power supply according to your configuration.

Determine how much power your computer needs to work in idle conditions, in full load and in overclock. From here you can start looking for the best PSU for you. It should have enough power to keep the system running, a bit over what the system consumes, so it can accommodate future upgrades, but do not overdo it, because you will end up paying specs you don’t need.


Know the specs

It’s true, a PSU does not have too many specs, in fact the only one you need to know is the power (the one measured in Watts). All the others are extra features that some power supplies have. Modular power supplies are those that have removable cables. They allow you to mount only the cables you need, making your case look better and making your work easier when doing the wire management. Efficiency is something you might want to keep in mind when buying a power supply. As tech journalist, Javed Anwar explains, efficiency is the power a PSU can convert from given amount of AC to DC. So, if a PSU has 80% efficiency rating, it will require 100W AC power (from the plug) to supply 80W to the computer. Better efficiency means lower power bill.

I’ll give you another example: my PSU is a 700W Nexus, it has an efficiency of 90%, so it gives around 600W of effective power. Now, my PC eats up around 400W, so I have 200W of power for future upgrades (such as a more powerful video card and more hard drives). Also, the bigger the efficiency, the less power goes to waste. The efficiency is rated by a power supply’s certificate. These are similar to medals, ranging from bronze to platinum, and in the table below, you can see the difference between these power supplies in three different loads: 20%, 50% and 100%. You can see that the higher rated PSUs have can maintain their efficiency above the 80+ mark in all levels of stress, and from this aspect the rating of the PSU is given.


Check the connectors

The number of connectors that the PSU offers is somewhat important. It’s true, you can never have enough of them, but just to be on the safe side, look for one that has more that you need. You might find yourself in need of a SATA power connector and you might find that you don’t have any free ones. Also, look closely to the CPU and video card connectors.

See if the PSU offers the newest 8-pin designs, these might come in handy if you ever upgrade your PC. Here are the most used connectors that your PSU will need to have:

  • Molex (4-pin) – used in just about anything from hard disks to fans or DVD Roms.
  • SATA – these are used in modern day hard drives or optical drives.
  • 4-pin/8-pin CPU – these connectors go into the motherboard to power the CPU.
  • 4-pin/6-pin/8-pin PCI Express – connectors for powering up the video card.
  • 20-pin/24-pin – the motherboard connector. This power the entire motherboard, and unlike the others, there is only one such connector per motherboard.

Always trust the brand

In power supplies, it’s always better to go for those coming from top manufacturers. They use quality materials, the have great efficiency and they come with lots of connectors that power your system with a smooth current flow. Here a few of the best PSU manufacturers, although there many other great manufacturers, these are just to give you an idea:

  • Seasonic
  • Sirtec
  • Antec
  • Cooler Master
  • Nexus
  • Enermax
  • Silverstone
  • Enermax
  • OCZ
  • Muskin
  • Corsair

Just to get you started

To give you a helping hand, we have put together a list of a few great power supplies. These come from respectable manufacturers that put a lot of effort in making top notch products. Look for something similar and you can’t go wrong with your PSU:

7. Antec High Current Gamer 400W
6. Cooler Master Silent Pro Gold 600W
5. Super Flower SF-600P14XE 600W Golden Green
4. Enermax Revolution 87+ 750W
3. Corsair Professional Series HX750 80 PLUS Gold
2. Seasonic Platinum 1000 SS-1000XP
1. Antec High Current Pro Platinum 1000W

If you haven’t figured it out yet, the PSU is very important to the system. And you should pay very close attention when you buy one. Keep in mind that the entire computer depends on the stability of the PSU, its efficiency and its levels of protection.

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