Powermizer interference in benchmarking

I am running CUDA 2.1 on a Mac Pro with two GeForce GT 120s, using the non-display device for computation.

Powermizer appears to place the GPU into a low power state following a short period of inactivity. This is fine in normal operation but I cannot find a way to disable it during application benchmarking. I have resorted to writing a temporary function to keep the GPU busy for two seconds before benchmarking begins but this is clearly a poor and unreliable method.

Powermizer can be disabled on both Linux and Windows. Is there a way to do this on OS X?