I've got a P4 3.2 GHz hyperthreaded with 2 gb ram  (no multicore/dual core/core duo stuff) cheapest vid card I could get when I got the pc (ati 9200 ish 128MB vidram) about 2 years ago now.

So about mid range PC for these days. 

Breaking things up into subscenes can get you around most system resource issues - I have some bryce tut's on my website that go into how I make my big images in bryce.

Dreams are just nightmares on prozac...
Digital WasteLanD