Very slow game speed Options

[Shadan]

I am planning to play an another BG2 run while we are wating for v6 release, but I have one serious problem. In all of my BG2 games (was 3 of them with IA) I experienced a very slow game speed in certain situations.
1. When there were lot of enemies and/or corpses on the screen (like githayanki suprem leader fight).
2. When there were many spellanimation on the screen (like SI, Mirror Image, GoI, Spell Turning etc.).
3. When I fought against big monsters (like any dragon).

It was very frustrating sometimes. First I thought it is because I have some mods (like bottomless Bag of Holding), but later I had only IA and The Four installed after ToB patch, Baldurash and EoU, and I dind't have bottomless Bag of Holding at this time. Despite this clean and modfree IA install, I had very slow battles still. My computer is not the newest, but I have 2 giga memory and I can play all games, even WoW without any difficulty. Can anyone give some advices how can I avoid this slow speed in BG2?
Ah, I played in 1024*768 resolution, but I tried in 800*600 also to check if this could be a problem.

[Shadan]

Thanks for answers. Sikret, I always had this problem in all of my games. I thought this is cause of bottomless bag of holding in my 1st game, later I didn't installed this component.

Raven, of course I am speaking about fresh install without any other addon than IA and The Four. (No bottomless bag of holding.)

I will check my freespace on disks, and I will do defragmentation only, but I hope anwser is in BG2 graphic options, since I don't know which should be turned on or off.
I will try disable Direct3D and DirectDraw acceleration , vertex padding as some of you recommended. I will rry to disable all graphical options like static animations, spell effects, VEF Vid cells, disable animations during fights, etc.
I would thank if any expert could give me an exact advice which graphic options should be turned on or off.

I am planning an IA free game now, since I have never played whole Ascension, Tactics, Tortured Souls so instead of tactical game, now I am planning a heavy role playing game. This slowing speed is not important in this game (even SI animation is turned off by mod in my currently started game since it is not so crucial if I am not playing IA). My primal goal to make sure I can play flawlessly without any slow speed in IAv6, what I am waiting eagerly. I hope its release date is not delayed too much.

This post has been edited by shadan: Jan 20 2009, 10:37 AM