I have a system that runs Windows 7 pro with one GTX 470 and GPU-Z continuously refreshing while in the background. When I run the Direct3D sample app from NVidia's NvPerfKit 188.8.131.5242, GPU-z's GPU Load flat lines at 0%. The NvPerfKit sample app uses NvPerfKit API to read the GPU idle sensor. While this sample app is running, I run Unigine Heaven Benchmark. While the rest of GPU-Z's sensors (core clock, memory clock, memory usage, temperature) seem to work by showing increased readouts, the GPU Load readout remains flat at 0%. When I re-run the Heaven Benchmark after closing NvPerfKit's sample app, GPU Load registers high GPU utilization. Does anyone have an explanation for this behavior? Thanks.