thank you zzpulp
before flashing my 3dmark06 : 3731 ( default setting : no AA, resolution 1200x800, optimal)
after flashing : 3dmark06: 4991 (default setting) (v550c750). Because i want it in safe range setting from v500c600 to v575c775 like yolda said. if i set too high , i think there's a risk of video card malfunction, right?
specs: 1.66 core duo, 1gb (553mhz) ram, 7900gsx