Hi,
I have a computer that posess these spec:
amd64x2 5200+ (2.7ghz)
8600gt
2g ram

I can run ps2 games with pcsx2 with an average of 35-50 fps(with speed hacks on)
So i was asking if it would run faster with another 2g ram (4g ram total)?

The ram would wouldn't give you much, if any, boost at all. Unfortunately your CPU is going to be your bottle neck for the most part. Though make sure you're using the latest beta (1736) as that could get you a few extra FPS if you're still using 0.9.6.