Gigabit Ethernet is now inexpensive and ubiquitous enough for home or small office networks. This week, we look at when Gigabit Ethernet is useful and explore how to add it without having to replace existing network hardware.

by Joseph Moran

In the beginning there was Ethernet, and it was good.

But, after a while, it wasn’t quite good enough.

So eventually Ethernet begat Fast Ethernet, which increased maximum performance tenfold from 10 Mbps to 100 Mbps.

Of course, “fast” is a relative term, so Fast Ethernet ultimately led to Gigabit Ethernet and another order-of-magnitude speed boost, this time to 1000 Mbps (which is, of course, 1 Gigabit).

Gigabit Ethernet has been around for around a decade, but only relatively recently has it gotten inexpensive and ubiquitous enough to be worth considering for the typical home or small office network. This week, we’ll examine when Gigabit Ethernet can be useful and explore how you can add it inexpensively and without having to replace existing network hardware.

What It’s Good For
Before we get into the hardware requirements, it’s important to understand when Gigabit Ethernet can offer a benefit and when it can’t. First off, it won’t do anything to speed up things like Web browsing or the uploading and downloading of files from the Internet, because those activities are limited by the speed of your broadband connection, not your local network.

But because it allows for a significantly faster connection than 100 Mbps Ethernet, in certain situations Gigabit Ethernet can help increase performance between compatible devices on your wired LAN. Not all network operations will benefit from Gigabit Ethernet, because many common and throughput-intensive ones like streaming audio and video (even HD video) don’t really tax even 100 Mbps Ethernet’s capabilities.

However, if you often have multiple users accessing the same network device, Gigabit Ethernet will provide more total bandwidth to go around, which should in turn result in less congestion and better overall performance. Gigabit Ethernet can also be helpful in situations when large (or a large number of) file transfers are involved, like when you perform backups over the network to a server or a NAS drive.

What You’ll Need
In order to set up a Gigabit Ethernet network, you need to have devices equipped with Gigabit-compatible network adapters connected through a Gigabit-compatible LAN switch. As it turns out, Gigabit Ethernet capability has pretty much been standard fare on desktops and notebooks for around five years now, so chances are good that your computers already support it. (The name of a system’s network card/chip in Device Manager will usually indicate whether it’s Gigabit-compatible or not.)

Upgrading older systems to support Gigabit isn’t prohibitively expensive, because PCI-based Gigabit network cards can usually be bought for only slightly more than 10/100 adapters-the former can cost as little as $20 or $25 when purchased online. (Though less common and somewhat more expensive than desktop versions, you can also get Gigabit-compatible Cardbus adapters for notebooks.)

When it comes to NAS devices, Gigabit Ethernet is becoming increasingly common, but it isn’t quite as ubiquitous on them as on computers. Many (though not all) of the NAS devices sold today are Gigabit-compatible, but that NAS you’ve had for a year or two probably isn’t.

Turning our attention to LAN switches, although the newest 802.11n-compatible routers incorporate Gigabit-capable switches — out of necessity, since the maximum data rate of 802.11n (248 Mbps) is more than double that of Fast Ethernet — the ones built into the majority of broadband routers (including the one you probably already own) support only 10/100 Ethernet.

But that doesn’t mean you have to replace your existing router/switch to add Gigabit Ethernet to your network, because simply connecting a stand-alone Gigabit-compatible switch to your existing switch will allow your Gigabit-compatible devices to use the faster connection. The good news is that like network adapters, Gigabit-compatible switches often carry only a minimal price premium over their 100 Mbps counterparts. (A typical example: as of this writing a 5-port Netgear FS605 10/100 switch is available at a major online retailer for $30, while the Gigabit-equivalent GS605 is only $10 more.)

What Goes Where
In the aforementioned example, when your router has a built-in 4-port 10/100 switch and you buy a separate 5-port Gigabit switch to connect to it, you’ll lose one port on each when linking the two. This leaves you with seven available ports — three 10/100 ports on the router’s switch and four Gigabit ports on the external switch.

The key is to make sure all your devices are plugged into the most appropriate port. Although all of the ports are part of the same TCP/IP network, connecting all your Gigabit-compatible devices to the free ports on the Gigabit switch will ensure they can communicate with each other over the fastest possible connection.

It doesn’t matter where you plug in non-Gigabit devices, since they’ll perform the same on any port. (Gigabit ports are backwards-compatible with 10/100 Ethernet, and plugging an older device into one doesn’t impact the performance of Gigabit devices connected to the same switch.) Of course, traffic to and from the Internet will still need to flow back through the slower 10/100 connection, but as we noted earlier, the bottleneck imposed by the broadband connection makes that a non-issue.

Adding Gigabit Ethernet to a home/small office network won’t necessarily knock your socks off with noticeably better performance at all times, but the costs are low enough and the potential benefits real enough to be worth looking into, especially when you’re in the market for network hardware.