In order to reach the maximum performance for your 802.11n device there are several key features which must be implemented.
The first and most important item is to have a wireless router that fully supports 802.11n.
What does this mean?
802.11n includes support for channel bonding. Although it's possible to implement channel bonding in 2.4 GHz, it will not be as effective as 5 GHz. The 2.4 GHz band has 3 channels, if you bond two of them together it will affect any other wireless routers nearby using this band. You can only have a single bonded channel in 2.4 GHz. It's also possible that nearby wireless routers using one of the bonded channels will cause interference on the 802.11n network reducing performance.
In the 5 GHz band there are many more channels available making it possible to have several wireless routers in the same location. This is the optimal solution to reach the maximum 802.11n speeds.
Antennas are another key element to improving 802.11n performance. More antennas will generally improve performance. Currently most devices have either two or three antennas.
Another important element is the full support for IEEE features such as the improved MAC features of short guard interval, packet aggregation and reduced interframe spacing (RIFS) which greatly improve the efficiency of the MAC layer.
In the table below you can see that having two spatial streams with channel bonding in the 5 GHz band and support for the IEEE short guard interval gives the best performance. Check with your wireless router manufacturer to see if your router supports all of these features.
This applies to: