Unreal engine 3 games all running badly?

[Mithness]

well i guess you couldnt say all becuase unreal tournament 3 and dead space both run decently but i bought tom clancys rainbow six vegas 2 and it runs like crap, it runs at a maximum of 30fps at lowest resolution and settings and the system requirements i am good with, but it still runs horribly same with the scourge project demo and mass effect 1, i don't understand why i can run mafia 2 better than those games and no clue why and i love RB6V2 it just runs like crap and i would love to be abled to fix this its just a really weird problem, maybe their just unoptiomized?

System specs (i know their not thatr good at christmas im building my own computer)
Amd Athlon 3800+ 2.4ghz
ati radeon hd 4350
1gb RAM
160gb Harddrive

 

[Herr_Koos]

Your system isn't very powerful, so some games are bound to run slow even on low settings. Make sure everything is patched and that your graphics drivers are up to date.

 

[jaguarskx]

You have a weak PC.

- A dual core CPU is recommended for that game.
- The HD 4350 is relatively weak. It's considered more of a multimedia card, not a gaming card.
- 1GB of RAM is rather small.

 

[Mithness]

i know its weak but Canyourunit says i pass the recommeded settings and no matter what resolution and settings i still get a crap FPS i just don't understand why Mass effect 2 runs better than the first one