Help for Win8 stuff, this is what worked for me anyways. Win8 is the devil.
I just fixed my NWN/WIN8 problems like WOAH.
I was getting terrible lag, reaching to unplayable levels if there was anything going on. Did all the normal stuff with the .ini, which helped but not as much as I was hoping. But I made do. When I tried to hunt more though (new character), it just was not working. So I looked around a bit, and found a few other things to try I hadn't seen mentioned anywhere else.
I did three things at once, so I'm not sure which worked the magic. I set audio to a 2D option (which I've seen mentioned, but apparently I forgot to try before), downloaded and installed the DirectX9c (I swear I did that before too... but here:
http://tinyurl.com/mruqufc, and having the more updated DriectX10/11 isn't enough it seems), and changed the color setting on the application (right click on the application, properties, use the compatibility mode for XPsp3, then 'reduced color mode' to 16bit).
Something in that fixed me getting lag at the lowest settings and smallest resolution, to running everything on max full screen with no problems. I haven't seen anything really spell heavy yet, but the instant change from what it was doing, to how it runs now is -amazing-. If anyone is still having Win8 issues, try that. The color thing was actually mentioned as a fix for a Win7 issue someone had, so that might all help for Win7 too..
Mags, that sounds like a lack of RAM/driver issues, or maybe the single core fix, or... so many things. making this old game work on new gear is such a pain.