Every so often, we get questions from people who plan to install Ethernet cable in their homes. The most frequent question we get is, "what's the difference between Cat 5e and Cat 6 cable, and which should I use?"
Around your house, you probably have either Cat 5 or Cat 5e wire. Cat stands for category. Cat 6 is cable that's more reliable at higher speeds than Cat 5 or Cat 5e. They look pretty much the same; in fact, Cat 6 is backward compatible with Cat 4, so you can mix and match. But they're labeled differently and they're different on the inside--where it counts.
Until recently, most home routers supported speeds of 10 or 100 megabits per second. However, Gigabit Ethernet routers have become more common. All three cables can work with Gigabit Ethernet. The old-fashioned Cat 5 cable is no longer a recognized standard, but it technically supports gigabit speeds--just not well. Cat 5e cable is enhanced to reduce interference so that it can reliably deliver gigabit speeds. However, Gigabit Ethernet still pushes the cable to its limits.
Cat 6 cable is full-on certified to handle Gigabit speeds--it's meant to handle it and it does it the best. It's also suitable for any 10-Gigabit uses that may come along someday; although at that point, you're pushing the limits of Cat 6. And let's not get into Cat 7 and it's fairyland of 40-Gigabit speeds.
Cat 6 cable also has more stringent specifications for crosstalk and system noise than Cat 5e does. That means you'll get fewer errors on a system operating via Cat 6.
Cat 6 isn't all roses though. Some folks think Cat 6 is harder to install. Cat 6 conductors are twisted more tightly, and there's more insulation. So if you need to cut cables you need to go a little more slowly.
Now for the cost: One hundred feet of Cat 5 cable will run you about $9. One hundred feet of Cat 6 cable runs a tad more than $11.
So my short answer is to choose Cat 6. But here's the longer rationale.
If you happen to have a bunch of Cat 5e cable, don't throw it away. It's useful for many more years, and it should serve you well.
If you're supercheap and can't stand the two dollar per 100-foot price difference, then sure, Cat 5e will do fine for the next several years.
However, if you're starting from scratch and want to be ready for whatever advances come down the line, you'll want to go with Cat 6 cable. You want to be as future-proof as possible. You wouldn't remodel your kitchen to look like 1992, right? Well, OK, maybe you would. But you wouldn't buy a 1992 model laptop, would you? Now you get me!