Most people who have owned a computer for a reasonably long time have inevitably had that moment where they go to turn on the PC in the morning and nothing happens. It just sits there dead. If that hasn’t happened, then perhaps it was this scenario: You are using your computer for your normal work and all of a sudden it reboots all by itself. You can find yourself in both of those situations for the same reason: A failing or failed power supply. After troubleshooting the power supply, or perhaps using a power supply tester, you may decide that you need to purchase a new one.
Even if your current power supply is in good working order, you may decide that along with several other upgrades that you want to also upgrade the power supply. When doing any major upgrade, like CPU, video card, or motherboard, it is a good idea to re-evaluate your power needs and see if a higher wattage power supply should be purchased as well.
Regardless of your reason for wanting a new power supply, you will likely find yourself wondering just which one to get. Are some brands better than others? How many watts do you really need? What connectors are a must-have, and how many? Let’s try to answer some of these questions.
No 2 Power Supplies are Created Equal
If you go to a computer parts website or store, you will find dozens of power supplies all boasting the same wattage and features, but from different brands and varying prices. Your first instinct as a frugal shopper is, of course, to grab the cheapest one and walk away satisfied that you got the same product for less.
Hold on a minute! I’m here to tell you that the off-brand power supplies do not perform anywhere nearly as well as a respectable brand does. You pay for more than just some connectors and wattage - you pay for quality and reliability. The fact is, even if a Cooler Master and a SuperDuperPower PSU claim to have the same wattage, the Cooler Master will run laps around the offbrand, no matter what. Buying a high quality power supply from a trusted brand means you can buy less watts and know that every one of them is performing at top notch.
How Many Watts?
The age old question when doing some serious power supply shopping is “How Many Watts do I Need?”. The answer to this question, of course, varies by what kind of hardware you are using or are planning on using in the near future. Each component of a computer is rated for varying power needs. You may buy a video card that says “requires 400w power supply or greater”. That does not mean that the card takes 400w on its own, but is rather the manufacturer’s best guess as to the power needed for both the card and the typical PC it may be installed in. If you’re running two of them, obviously you’ll need more. But how much more?
Thank god the smarter among us of have heard our pleas for help and devised a nifty calculator to help us figure it out. These are available all over the net by searching “power supply calculator”, but I like the one Newegg.com offers. I like everything Newegg offers. You’ll need to know details about the hardware you are currently running, which you can find in your computer’s documentation, online, or in System Information.
The Connectors. They Confuse Me.
I know, the first time I plugged in a power supply I was a little confused myself. Then I went to school. But you don’t need school, because you have me and the plethora of helpful links that I am about to provide you. Power supply connectors are pretty straight forward to plug in so long as you know you’re getting the right one. As a basic reference, new motherboards take 24-pin P1 (main) connectors. You need more than 2 SATA plugs these days. New CPUs take 6 or 8 pin connectors, and older ones take 4. Newer video cards take 6 or 8-pin power plugs that are clearly marked as PCI Express plugs. You’ll need some Molex’s too for the incidental fan or drive. For more help with power supply connectors, I recommend reading about M.S. Smith’s Noodles, or my legos. “My Legos 2” is pretty good too.