hi my friends…i would like to know some thing like this …so listen up

i heard zbrush use to make maps and the rendering part done in another 3d application like 3d max ,maya… is this the normal process that we should follow…cos i can’t export my model again in to maya or max cos so far it has 700000 polys and the machine gets slow down
…i 've got a 3.2 normal processor and 512 ram…is it enoug to do so…or is it a my fault when i’m exporting them into maya or max
so plez tell me & help me to solve these problems
i 've never textured any of my head busts in max or maya…so plez …thanx in advance