uhh well the Ghz don't actually do **** so what are the MB? do you have the name of the graphics card? know what kind of slot it goes into? Assassin's Creed 1 or 2? and what do you mean a ps3 game is it not a pc game?
here is the minimum system requirements for Assassin's Creed 2:
processor: Dual core processor 2.6 GHz Intel
Pentium
D or AMD Athlon
64 X2 3800+ (Intel Core
2 Duo 2.2 GHz or AMD Athlon 64 X2 4400+ or better recommended)
RAM: 3 GB Windows XP / 2 GB Windows Vista
Video Card: 256 MB DirectX
10.0-compliant video card or DirectX 9.0-compliant card with Shader Model 3.0 or higher (see supported list)*
Sound Card: DirectX 9.0 or 10.0-compliant sound card (5.1 sound card recommended)
DirectX Version: DirectX 9.0 or 10.0 libraries (included on disc)
DVD-ROM: DVD-ROM dual-layer drive
Hard Drive Space: 12GB