Shadows Kill. I did a test render: 14 P4 figs 43 lights, 12 shadow-casting somewhat 'polished' floor, only slightly reflective, not a mirror. Dual AMD 1.4G 1G RAM Took an hour to process the shadows and only 9 minutes to complete. Ray-tracing, shadows set, all the rest at default RAM usage stayed within the physical limits, so no disc-flogging.