This is a bleeding edge laptop.  I got it last September, but it has kept up with the pack because I overloaded it at the time.  I've got 4 gigs of RAM (though I’m running 32 bit, so you know the story with that), with a Core 2 Duo 2.4 Ghz T7700.  The video card is an NVIDIA GeForce 8600M GS.  Supposedly it is fully discrete and not relying on system memory.

I don’t really notice any performance difference when I’ve got hardware shading turned on.  I can fly around the scene with my 3DConnexion mouse just as quickly and smoothly as I can without it turned on.  But admittedly, I only have about 1 figure, several cloth items, and some strand based hair loaded.  But it is a butt-load of hair.  Once I add more figures I might have more trouble.  But anyway, the shadow “problems” don’t really seem like a memory issue.  Maybe I should pay a visit to the openGL settings as you suggested.  Another thing is that changing the shadow settings on my lights in poser makes not apparent difference in the preview window.