LINK
This WIKI is also a great resource for online players.
LINK
1. Tree problems? This will fade surrounding trees out almost completely. It will give you both better performance and better view of your surroundings.
In your nwn2.ini(My Documents\Neverwinter Nights 2) under [Display Options].
Try the following settings:
ObjectFade Start=0.0
ObjectFade Length=0.5
ObjectFade Percentage=.01
2. Turning down your graphics. Believe it or not turning down your graphics a bit will help your online play performance.
3. Direct connecting to the server. When you log into the first multi-player menu you have the options of "New Game" "Load Game" "Join Internet" "Direct Connect" etc. Choose the "Direct Connect" option and enter 71.5.34.137.
4. Do not send a /tell to someone who has just logged into the game. When you see someone log into the PW you want to talk to give them at least two full minutes to load before sending them a tell. What happens is the games says you have logged into the PW when in fact you are still loading. If you receive to many tells while loading you will freeze up.
5. Never go AFK in an area inhabited by monsters. Each area has a clean up script that keep the PW running smoothly. But they only run when an area is empty.
6. Turning off shadows or at the very least, setting shadows to low quality will increase performance by a huge amount. Shadow settings are the single most important thing you can do to impact performance.
And for more information: The Neverwinter Nights 2 Tweak Guide