Map had no doors, or curving tunnels and so required no Area portals, It was also 1024 x 512 compared to the 2048^3+ size of my old, unoptimised one.
I also stick vigourously to the grid, dislike clipping and operate with most trim being triangles/rectangles/squares to assist VVis.
That is why I'm confused. If anything it should have gone faster. Maybe it's a sign I should finally get off my single core cpu!
Anyway, enough offtopicness.
Ontopic, demanding moar eyecandy here!