Why is my wifi speed slower than ethernet connection?

September 5, 2006 5:05 AM

Is it common for the speed of a residential wi fi connection to be significantly less than a plug-in ethernet connection? My ethernet is getting 7.1 mps while the wifi chugs along at 1.6 mps. Is there anything I can do to increase the speed? Is this something to do with the wireless router itself (which is 4 years old)?
posted by quintno to computers & internet (7 answers total)

What router model are you using? The protocol can certainly limit your throughput, as can the signal quality (it ramps down the speed to get a stable connection if a poor signal is at issue). How far away is the router from the computer in question? Is it a laptop? Does the speed stay constantly low even at close range?

More info is needed.
posted by empyrean at 5:30 AM on September 5, 2006

It sounds like you might be using an 802.11b (now called sometimes called "Wireless B") wifi access point. You report your speed as "1.6 mps" -- depending on what letter comes between "m" and "p" you might be hitting the max speed of your wireless network. 802.11b has a max speed of 11 megabits per second and a typical speed of 6.5 megabits per second. If you are getting 1.6 mBps (mega BYTES per second) you may well be bumping into the top speed of the network. In that case you can increase you speed by upgrading to 802.11g (Wireless G) or the even newer 802.11n gear. 802.11n is still a draft specification, though, so you may want to wait a bit before taking that step.

That's a pretty zippy little internet connection you have, though. Is it DSL? Cable?
posted by The Bellman at 5:48 AM on September 5, 2006

Purely anecdotal, but if you're running an old Linksys WRT54G, I saw a significant speed increase and a much more stable connection once I replaced the built in Linksys firmware with DD-WRT. It's an alternative firmware with a pretty slick GUI and a bunch of added features, like the ability to boost your routers radio output far beyond the default and to use your router as a commercial hotspot.

There's also the open source project OpenWRT. It's extremely robust and extensible but a lot less user friendly...basically a Linux distribution for the router. I've been told by friends that they've also seen performance increases after flashing their routers with that one. You'll just need to be more comfortable with the command line interface.

> You may not be using a Linksys but I figured they're so common I'd take a guess.
posted by JaredSeth at 6:23 AM on September 5, 2006 [1 favorite]

You should note that when they say 802.11b is "11 Mbps", that's really the signalling rate. With CSMA-CD networks, line 802.11b, you typically only get a throughput of 30% of the signalling rate. You get less if there are multiple computers on the network or if there's interference/noise.

This used to happen in old 10 base 2 wired ethernet networks, which is why everyone has moved to 10 base T and star topologies.

Are there any sources of noise in the 2.4 GHz band? Do you have a neighbour running a wireless network?

Also, depending on how you measured it, you may not really have a 7.1 Mbps connection. That's faster than the average home connection and caching can throw off speed measurements.
posted by GuyZero at 6:49 AM on September 5, 2006

Yes, A typical wired ethernet connection will be 100mbps (the small b is for bits) which comes out to about 12.5mBps (Big B for Bytes). That's at 100% efficiency, without overhead. The fastest wireless is 802.11g which is a 54mbps (small b again) connection, which is 6.75mBps. Once again that doesn't factor in overhead, which there is quite a bit of in the wireless protocol. If it's 802.11b, which only runs at 11mbps (1.37mBps) the throughput is of course lower.

The main point though is that even assuming maximum wireless signal strength, wireless contains more overhead data to be transmitted along with the actual data.
posted by borkencode at 7:59 AM on September 5, 2006 [1 favorite]

I'm using a Netgear access point with 802.11g. However, the laptop (which is one floor away), can only receive 801.11b. It does indicate, however, that it is receiving 11.0 Mbps--however, when I test the speed on a site like bandwidthplace.com, it's down to 1.3 Mpbs. I am using Cable.
posted by quintno at 8:39 AM on September 5, 2006

It does indicate, however, that it is receiving 11.0 Mbps--however, when I test the speed on a site like bandwidthplace.com, it's down to 1.3 Mpbs. I am using Cable

11 megabits is the wireless connection speed between your laptop and your wireless router. 1.3Mbps is the connection speed between your router and the rest of the world (or at least to that bandwidth test site).
posted by mrbill at 8:47 AM on September 5, 2006