The difference between an ethernet splitter a hub and a switch

Ethernet splitters, hubs, and network switches can all be used for expanding and improving a network. Each of these devices has its own unique strengths and weaknesses. In this guide we’ll go over how each of these handy network devices work, how they differ from each other, and how each one is best used.

Ethernet splitter

Ethernet splitter

The cables in most home networks contain four twisted pairs of wire. That’s eight wires in total. Cat 5e is a common example of this. 100BASE-T is an ethernet standard which handles network traffic at a nominal rate of 100mb/s.

Here’s where it gets interesting. 100BASE-T requires only two twisted wire pairs. Just four out of the eight available wires in a Cat 5e cable. So if we’re only using half of the wires in the cable, couldn’t we make one cable act as two cables? Why yes! We can! And that’s exactly what an ethernet splitter does!

In the diagram below, the red wires represent data connection A and the blue wires represent data connection B. Grey represents unused wires.

Ethernet splitter infographic

If you have two devices in one room and a router or a switch in another room, a splitter could come in very handy. Instead of needing to run two cables from one room to the other, only one would be necessary.

Typical use for an ethernet splitter

Of course, you could always run one cable into the other room, then split it into two connections with a hub or a switch. So why would you use a splitter at all? Two words:

  • 1. Cost
  • 2. Power (consumption)

The cost of an ethernet splitter is typically a lot less than the cost of a switch, hub, or router. Plus, splitters don’t need no stinkin’ power supply, making them pretty darn handy indeed.

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The splitter comes with several drawbacks. First there’s the 200mb/s limit. That’s 100mb/s per connection (100BASE-T). That is of course a nominal rate, or what some people would call the “maximum” or “theoretical” rate. Real world results will vary. The next weak point here is the need for two ethernet ports on both ends. We’re not actually creating any more ports. All split connections (with an ethernet splitter) must be un-split on the other end. We’re really only combining two connections into one cable at one end, then un-combining those two connections back into two physical cables at the other end. Perhaps a better name would be “100BASE-T Combiner/Un-combiner”. I think that would be much more descriptive of what these things actually do.

An ethernet splitter will not do this:

Ethernet splitter and two computers without a router, switch, or hub

Replace the splitter in this diagram with a hub or a switch and you’re good to go.

Ethernet hub

Ethernet hub

Hubs make more ethernet ports by basically repeating network traffic. Actually, a hub kind of works like a splitter sounds like it should work. You connect a router to a hub in another room with a single cable. You then connect multiple devices to the hub.

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Regrettably, hubs repeat all of the network traffic that is sent to them. All of it. That’s good because it extends the network, creating more connection points. It’s bad because repeating everything hogs bandwidth, slowing down the network. If you don’t have too many devices consuming network bandwidth at the same time, this probably won’t be a problem. Generally speaking, however, there are better ways to do this for not much more money.

Network switch

ethernet network switch

Meet the switch. It’s the most expensive of the three. But it’s worth it because it’s magic. Magic you say? Yup. Using the magic that is packet switching, network switches are able to figure out which devices are trying to connect to each other and connect just those two. No need to burden the rest of the network with all that extra bandwidth! The difference is kind of like using walkie talkies to communicate over a distance instead of just yelling very loudly.