Networking – Internet speeds significantly slower on wireless connection versus wired connection with D-Link DIR-655 Router


I just bought a D-Link DIR-655 router, and I've noticed a significant difference between the wired and wireless speeds when browsing the internet. My cable connection is supposed to have a speed of 20 Mbps, but I noticed today that I can only get about 11 Mbps over a wireless connection. Running the same test (using, I found that I could hit just over 20 Mbps using a wired connection, so the internet connection isn't the problem.

I've tried adjusting the channel to Channel 11 (rather than letting the router choose – it was on Channel 1 to begin) after looking at the other channels in use in this area. I even tried disabling the encryption (WPA2) to see if that would help, but it didn't. The wireless card in my four year old laptop can't do 802.11n, so the router is set to connect on G only.

The Dell utility that came with the driver for the wireless card (built-in, not external) on my laptop shows no significant noise on the connection. Windows (XP, SP3) is showing the connection has 'Excellent' signal strength and the speed there is reading as 54.0 Mbps as is normal for a G connection.

I'm not sure what else could be disrupting the signal. The router is unfortunately right next to a speaker, and there is a cordless telephone in the room, but I would have expected that these devices would show up as noise in the utility if they were a problem. My assumption is that the problem is with the router itself, but I am unable to determine how to confirm/correct this.

Any suggestions would be much appreciated.

Best Answer

Usually on G wifi, from my experience the real speed is around 12 mbits. Here is a table with theoretical speeds:

  • 802.11b - 11 Mbps (2.4GHz)
  • 802.11a - 54 Mbps (5 GHz)
  • 802.11g - 54 Mbps (2.4GHz)
  • 802.11n - 600 Mbps (2.4GHz and 5 GHz) - 150Mbps typical for network adapters, 300Mbps, 450Mbps, and 600Mbps speeds when bonding channels with some routers
  • 802.11ac - 1300 Mbps (5 GHz) - new standard that uses wider channels, QAM and spatial streams for higher throughput

Below is a breakdown of actual real-life average speeds you can expect from wireless routers within a reasonable distance, with low interference and small number of simultaneous clients:

  • 802.11b - 2-3 Mbps downstream, up to 5-6 Mbps with some vendor-specific extensions.
  • 802.11g - ~20 Mbps downstream
  • 802.11n - 40-50 Mbps typical, varying greatly depending on configuration, whether it is mixed or N-only network, the number of bonded channels, etc. Specifying a channel, and using 40MHz channels can help achieve 70-80Mbps with some newer routers. Up to 100 Mbps achievable with more expensive commercial equipment with 8x8 arrays, gigabit ports, etc. 802.11ac - 70-100 Mbps


Right now, I've 802.11n network @ home, but even the router and my PC says it's connected @ 300 mbit, I can get only about 20 mbits real speed through a wall.

The Wifi "standart" speeds are not achievable in typical conditions, it sounds to me more like marketing speed.