Hi eric.

Unfortunately, although Simlab is without doubt a very good product and very easy to use, it lacks many advanced features .

One of these is the GPU support.

From their web site : "...Composer, and optimally parallelized by taking advantage of all CPU cores available in the machine...."
and "...Fully CPU-based rendering..."

Read at : http://www.simlab-soft.com/technologies/simlab-rendering.aspx

So, no chance to speed up things by GPU. Only CPU support.

This is one of the reason I decided not to purchase a license.

Bye.

Marco (mkdm)