hello comrade 5yka, i am a gamer at times and tweaker at the most, tweak what is given that will be software to the maximum & hardware at minimum or none .
my system specifications are
Intel dual core 2.5 ghz
2 GB ddr 2 ram
160 gb ram
asus p5n73 am motherboard(on-board pci xpress card)
get in the game go to options and click the anisotropic filtering,drag it to the left (it is similar to brightness slider)
turn off the anti aliasing .
this must help, get a new agp 8x or what is acceptable by your motherboard . increase your virtual memory, this must work even in wine,cedega,crossover in any Linux(I hope)