do i have a good enough PC for assassin's creed?

[aprendiz]

Hi, I wanted to ask somethign because i just can't figure ut why.
I got assassin's creed one and two for PC, and although they run pretty smooth i still have some lag and i have to turn off some ooptions in the graphics panel to be able to play smoother, i have read the sys req for both versions and as far as i can tell my pc have the recommended sys req so they should be lagged at all, so this is my pc

Windows XP SP2 32-bit
4GB RAM
AMD phenom X3 (triple Core) 2,1 Ghz
NVIDIA GeForce 9400 GT with1 GB of memory

and these are the sys req for assassin's creed 2, so please chack them your selves


Recommended System Requirements
OS: Windows XP/Vista/7
Processor: Intel Core 2 DUO E6700 @ 2.6 GHz/AMD Athlon 64 X2 6000+
Memory: 2 GB
Hard Drive: 8 GB Free
Video Memory: NVIDIA GeForce 8800 GT/ATI Radeon HD 4700
Sound Card: DirectX Compatible
DirectX: 10
Keyboard and Mouse
DVD Rom Drive



please tell me