Computer power cord AWG: Why it matters

If you look at your PC power cord really carefully, you’ll see a number stamped on the side followed by the letters AWG. What does a computer power cord’s AWG mean, and should you worry about it?

With a typical desktop computer, even a light-duty power cord is sufficient and you don’t have to worry about AWG. High-end computers like servers or gaming computers with high-power video cards in them do benefit from a heavier-duty power cord, such as 16 AWG or even 14 AWG. Using a heavier cord than the manufacturer specified won’t cause any problems, but a too-light cord can cause power issues.  

PC power cables are all the same, right?

PC power cables all pretty much look the same from the outside, but no, they aren’t all the same. If you’ve ever unboxed and deployed a server, you probably noticed the power cables that came with those servers are a bit thicker than the ones that come with desktop PCs.

computer power cord AWG
Who knew this innocent-looking power cable could be controversial?

Using the power cable that came with the Dell Optiplex sitting on your desk on a server can cause heat issues. If the server is under very heavy load, it can theoretically pose a fire hazard. If a supervisor told you not to use a desktop PC power cable on the server, that’s why.

The tell-tale sign is to touch the power cable while it’s in use. If it’s warm or hot to the touch, you need a heavier cable.

AWG power cord meaning

AWG stands for “American Wire Gauge.” Gauge is simply the thickness of a wire. Therefore the number printed on the power cord refers to the thickness of the wire, measured in gauge. Lower is thicker. Standard PC power cables use 18, 16, or 14-gauge wire.

Assuming the printing hasn’t faded away, along with the AWG rating of the wires inside, the cable will also say what amperage draw it’s rated for. Thicker wire allows for more amperage. Usually you can also find amperage ratings molded onto the power connectors themselves.

Thicker wire also reduces voltage drop. But unless you’re making a super-long PC power cable, voltage drop from your power cable shouldn’t be an issue in PC applications. You have to go to extremes to get the voltage to drop more than a couple of volts, and PC power supplies are designed to be able to run off 110-volt current while most houses give 115-120 volts these days. You’ll run into heat issues before you run into voltage drop issues in this case.

14 AWG vs 18 AWG power cord

A light-duty 18 AWG power cord is good for about 5 amps. That’s OK for a PC with up to a 600 watt power supply. Above 600 watts, assuming your computer is actually using that much power, you push the limits of an 18 AWG power cord and can expect the cord to heat up and possibly malfunction.

A 14 AWG power cord is good for 15 amps. That’s more than you need unless you have an 1800 watt power supply and, again, you’re actually using it. We’re talking Bitcoin mining rigs here.

Most enthusiasts only need a 16 AWG PC power cord. For that matter, if your gaming PC has a 600-watt or smaller power supply, an 18 AWG cord is fine.

There’s no harm in using a big ol’ 14 AWG cable if you don’t need it. But if you don’t already have one and have to buy one you’re wasting a little money. At a length of 6 feet, a standard 18 AWG PC power cable costs around $2. A 16 AWG PC power cable costs around $3. A 14 AWG PC power cable costs around $4. If you want to be really safe and get an overengineered cable, at least we’re not talking about a huge cash outlay.

How much power does my PC use?

In the 90s we definitely tended to underestimate how much power our PCs used because 300-watt power supplies were hard to find and crazy expensive. In 1996, PC Power and Cooling charged $99 for a 250-watt power supply. Their standard 230-watt model was $59, which was still expensive compared to the 230-watt boxes your local computer store sold. A 400-watt box cost $200.

Today it’s not hard to find a quality, reputable 400-watt power supply for $40, so there’s no reason not to get one.

Power consumption jumped during the Pentium 4 era, but in recent years it came way back down to reasonable levels again. If your video card doesn’t require a dedicated power connector from your power supply, you’re probably in the 200-300 watt range, if not less. If you have multiple high-end video cards, you may get your usage up over 600 watts.

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