bad preformance in TNT2 (aperture size)

[Kintoke]

I found the problem of the hang up, or crash in games...it whas the "agp aperture size". When I select an option form the 16mb to 128mb, the games crashed, so I put 8mb or 4mb. The only thing is that the games runs very slowly, I did the 3d mark 2000, and told me that I have 1730!!! in a p3-500, so I am not getting good preformance. Can somebody help me fix this, or tell me how can I improve the preformance in my system??
Thanks.

My spec are:
P3-500
128 Ram
Viper V770 Ultra (tnt2 ultra)
SB LIVE!