ok so after a bunch of testing.  if you use raytracing shawdows instead of shadow maps, you will get faster results.  why?  (someone correct me if I am wrong)  the shadow map part of the rendering engine is not multithreaded (its part of the startup of the render).  Raytracing is handled in the thread, so each section gets its own processor (if you have more than one).  On a simple render with shadow map vs raytracing at .25 it was 37 to 25 seconds on an Opteron 170.  i intend to make a more informative post with pix when I am back from vacation.  all I have out here is an athlon 2800 barton (lol)!