router: Asus RT-N16
dd-wrt: v24-sp2 (12/20/11) mega (SVN revision 18024)
initial wireless tests (LAN and WAN) both gave 17-18Mbps down and upload to internet 5Mbps up.
first issue was it was set to G-Only for wireless mode.
i switched that to G/N Mixed.then the googlez gave me these links that did the trick:
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=533486
and
http://www.dd-wrt.com/wiki/index.php/Wi ... figuration
i did the following, testing after each change in case one made a bigger difference than another. some work in conjunction, so not doing one may result in slower performance if the corresponding setting(s) are not also done.
-Channel width to 40MHz
-Frame burst to enable
-Preamble to short
-Shortslot override to short
-WMM to enable
-No acknowledgement to disable
-CTS protection to auto
-Left/right antenna to auto
-Network mode to NG-Mixed
-ACK timing to 0 or 300
-Make sure security stays at WPA2-AES
-Select wireless channel manually picking the least used one
the biggest improvement came from decreasing the ACK timing (default at 2000) to 300. that alone bumped up my download speed to 25Mbps.
from the wireless-N config article above, i also tried playing with Tx power, but anything i did from the default of 17 just slowed things down.
disclaimer: i assume many of these settings will be router-specific and YMMV. the most variable portion is probably the channel selection and using upper/lower mode, as interference will vary depending where you live. i have about 20 other wifi networks in the area, so it's slim pickings for me.
end result: 26Mbps down / 5+ Mbps up (internet)...a nice little bump for my laptop. my phone and tablet seem to have benefited a bit more than the three year old laptop.