Running Neverwinter Nights 2 but not getting those framerates you wanted? Neverwinter Nights 2 is a very enjoyable RPG experience along the lines of such classics such as Baldur’s Gate and Planescape but its also has a very complex graphic engine. Here’s what you can do to make Neverwinter Nights 2 run faster on your PC. System Requirements included. Oh one “tweak” to make NWN2 more enjoyable? Crank up those speakers especially during spoken lines between party members. Priceless.
How to make Neverwinter Nights 2 run faster

1. Make sure your system specs are ABOVE the minimum requirements listed at the bottom of the page, NWN loads a lot of data so you might want one of those faster hard drives. as always having a faster proccessor and larger memory also helps a lot. My observation is that if your system can handle Bethesda’a Oblivion then you shouldnt have any problems with NWN2.
2. Defrag your system.
3. Install up to date system drivers. This step can fix a lot of your problems.
4. Disable Vsync for NWN2main.exe. This can be done through the Nvidia Panel for Geforce users.
5. Check your game’s graphic settings. Disabling Shadows helps a lot of users. Lowering the resolution can earn you extra framerates, same as disabling Bloom and Water effects. Lower Draw distance also helps espcially with older cards. The advanced Graphic setting tabs has a
couple of editable settings, just pick the lower quality option for faster performance.

Possible performace increase for AMD users
If you?re an AMD user. There is an nwnamd.exe file in your install folder. Some AMD users say this helps them out considerably, others report no change.

XFIRE Performance problems
TURN OFF XFIRE. Even though it?s offered as an install with the game, it causes *massive* slow downs with just about everything. Alternatively, you can use the Xfire work around here.

Drive camera fix
CameraFollowAlways=1
Drive camera no longer floats off if you turn around.

Remove intro movies
Rename the .bik files in your movies folder, you?ll see which ones to rename, like wotclogo.bik, etc. This removed all the stupid movies that load when you boot the game.

Slates UI Mods here.
WoW Style camera controls here or here.
How to ?De-Level? and re-roll your character here.
Black chat box problem FIX here.
How to play the official campaign without using henchmen (sorta) here.
UI changes to the text box here.
5.1 Sound not working correctly. Fix here.
Get a full Watch uniform from the watch quests instead of just a cloak here.

via source

System Requirements:

Recommended:
3 Ghz Intel Pentium 4 or equivalent processor
1 GB System RAM
ATI X800 series, NVIDIA GeForce 6800 series, 256 MB, or higher video card

Minimum System Requirements:
Windows XP, Windows 2000
512MB System RAM
2.4 Ghz Intel Pentium 4 or equivalent processor
Hard Disk Space: 4.9 GB free hard disk space
128MB Direct3D compatible video card and DirectX 9.0 compatible driver;
DirectX 9.0c (included)
DirectX 8.1 compatible sound card
DVD-ROM Drive: 6X speed or faster
Keyboard, Mouse

Supported Video Card Chipsets:

ATI X1950 series
ATI X1900 series
ATI X1800 series
ATI X1600 series
ATI X850 series
ATI x800 series
ATI x700 series
ATI x600 series
ATI Radeon 9800 series
ATI Radeon 9700 series
ATI Radeon 9600 series
ATI Radeon 9500 Pro
NVIDIA GeForce 7950 series
NVIDIA GeForce 7900 series
NVIDIA GeForce 7800 series
NVIDIA GeForce 7600 series
NVIDIA GeForce 6800 series
NVIDIA GeForce 6600 series
NVIDIA GeForce FX 5700 or above