Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I found out that my acccespoint supports dual band (LinkSys E3000), so I went to its settings and changed it from operating on 20MHz to 40MHz.

Does this mean I get better speed now? Or have I misunderstood how this works?

share|improve this question
1  
Are you asking about the 2.4GHz band or the 5GHz band? – David Schwartz Jan 26 '13 at 23:44
up vote 19 down vote accepted

From here:

http://homekb.cisco.com/Cisco2/ukp.aspx?pid=80&app=vw&vw=1&login=1&json=1&docid=e1ec57e167054575a8a7b924e23ee10e_Manually_Configuring_the_Wireless_Network_of_your_Linksys_Du.xml

NOTE: The wireless network modes for a Linksys Dual-Band router will vary depending on the frequency band(s) you choose to enable. In the 2.4 GHz frequency, the Wi-Fi signal range is divided into channels each at 5 MHz interval. Adjacent channels overlap and will interfere with each other at 20 MHz block. Setting the channel width to 40 MHz network will allow you to use 2/3 of the entire Wi-Fi band. Thus having a higher chance of overlapping and interfering with other wireless networks. Meanwhile, if you set the channel width to 20 MHz, the network will only overlap with the two channels before and after that frequency.

You won't get better speed by doing that change. You may get better signal, but there's a downside to it. Essentially, you will have a higher chance to have collisions with other wireless networks around you. I would keep it at 20 just so you have less packet loss.

Dual-band routers essentially give you two access points with each having their own bandwidth in them. Usually one AP will be in the 2.4GHz range and the other will be in the 5.0GHz range. Within each spectrum, there are several Wi-Fi modes that you can enable. The fastest will be Wireless N, with speeds of 300Mbps. However, that 300Mbps is shared between all devices connected to that AP.

For example, if you have 5 devices in the 5GHz AP and one is using up 200Mbps, then the other 4 devices on the 5GHz AP will have 100Mbps to work with.

However, both AP's are isolated from each other (wirelessly anyways; they have the same IP address so devices on different APs can still contact each other), so if you have two data-hungry wireless devices you could put one in the 2.4GHz AP and another in the 5.0GHz AP(assuming it supports 5GHz Wi-Fi).

If you want to get the fastest speed out of your router, enable both the 2.4 and the 5.0 APs, configure them with wireless N, and split your devices across each network evenly one by one.

share|improve this answer
    
2.4GHz and 5GHz. – Hennes Feb 3 at 7:21
    
Also regarding last paragraph. the 5GHz band has less range and possibly more speed and fewer overlapping channels. – Hennes Feb 3 at 7:22
    
Link now redirects me to linksys.com/ca/support-article?articleNum=139627 , which has the same cited text. Thought I'd preserve it in case of link rot. – Mathieu K. Apr 19 at 4:02

yes if your NIC supports channel bonding setting up your wireless to 40Mhz will make double troughput as you get double connection speed and depend on your wireles NIC you can can up to 300Mbpx or even theoreticaly up to 600Mbps speed and this meen you have a higher real speed. But at 40Mhz you will have a bigger chance for channel overlaping and interfere with other wireless devices.

share|improve this answer

I just want to point out a huge misconception about "splitting your devices evenly across networks" that is propagated in the accepted answer. There are some very limited use-cases when 'strategically' connecting your devices to either 2.4 or 5GHz network might be beneficial, however under normal usage you should absolutely not do that. Moreover, I cannot think of a single usecase when the above procedure should be done as clumsy as described.

The correct way to go is: simply connect all your "speed-hungry" devices (laptop, tablet, smartphone) to 5 GHz network. It is a faster network with lesser interference. The more devices connected to it → the better for them.

Put all other — not "speed-hungry" — devices (like printer, 'smart-toothbrush', Nest thermostat or whatnot nowadays) on a slower 2.4 GHz network. Don't worry, they will be able to communicate with 5GHz-devices just fine, but keeping them off 5GHz network might help preserve high speeds and low latency for those devices that actually need it.

Nevertheless, the fast 5GHz network has limited range and penetration capabilities, so at some point in your house you will probably notice that devices have trouble connecting to it. This is exactly the point when 2.4 GHz network comes in handy once more, because having full reception on a slightly slower network is always better than barely being able to connect to the fast one.

share|improve this answer

protected by Community Dec 18 '15 at 22:11

Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site.

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.