How sculpt on a too slow computer?

Having tried out sculpting with Blender before with smaller meshes like faces and similar, I haven’t had a problem, but when trying with a whole character, I suddenly realize my computer is way too slow and can’t handle the poly count. I’m hoping that someone well versed in Blender sculpting can answer my questions, namely this:

-Do a high poly model for normal mapping have to be in the same file as the low poly model to be able to bake?

-Can I copy, or duplicate, specific areas of the low poly model over to another file and work it up to high poly there, and then import it back to the original low poly file to bake it?

-And, if the above isn’t possible and I simply have to work with the high poly model in the same file as the low poly one to be able to bake it - how on earth do people handle so heavy meshes - is there something I have missed?

I can subdivide my character (currently at approx 2500 polys) two or three times only before Blender crashes on me, and that is not enough to sculpt with, I’m afraid. I’d loath to have to buy Z-brush only for the reason I can’t do the same in Blender, since Blender now has this awsome feature - but if I can’t use it, what’s the point?

My comp has 2gig ram, AMD sempron processor 1.80 GHz. If that ought to be enough or not I don’t know. How do you people usually go about doing high poly meshes - push vert by vert? :confused:

I remembered an earlier discussion on this topic … the info in this thread may help:
http://blenderartists.org/forum/showthread.php?t=131319

i found that turning off subsurf helps a lot…

That thread seems to answer all my questions, thank you Cire! :slight_smile:

@ ward7299: Should I rather sculpt with multires than subdivide, then? I thought multires would slow it down more, but I’m just a noob when it comes to high res models. :confused: