I am using Poser 7 on a dual core 64 Athlon, and do my renderings in two threads.

It occurs tome that obviously either processor takes one thread: one processor takes the top half of the picture, and the other the bottom half. Now taht is fine, but since the complex bits (face and hair) are in the top half of the picture, I find that the processor doing the lower half is finished and runs idle while the other processor is still toiling on the hair, and then still there is the rest of the top half to do.

Is there a way to let each thread say start at an end of the picture (one top-left, the other bottom-right) and meet wherever they meet?
I do contemplate tilting the camera by 90 degrees and let so both do a share of the difficult parts.
Any other ideas?