Poor Wi-Fi performance : Intel PRO/Wireless 3945ABG

Solution 1:

You could be seeing slightly different symptoms of the same wireless N problem that I was having with my Intel card. This is what fixed mine (reference Why does my wifi Internet intermittently disappear?):

Try typing the following commands at a terminal. These will turn off your ethernet port and disable the wireless N in the wifi driver. It is not permanent and will revert the next time you reboot:

sudo ifconfig eth0 down
sudo modprobe -r iwlwifi
sudo modprobe iwlwifi 11n_disable=1

If that works for you, there's a bash script on my Github that you can download and run each time you reboot: https://github.com/FreedomBen/handy-bash-scripts/blob/master/fixTheInternet.bash

I have this script on my desktop and I just run it each time I reboot. I haven't had any issues since.

Note: You will have to make the script executable. At a terminal, type:

cd path/to/script
chmod +x fixTheInternet.bash