Quote Originally Posted by STaRGaZeR View Post
A quad core that is not loaded to at least 95% means the application is not well multithreaded!
Huh? This is a joke, right?

Yes, if it was a pure number-crunching app that was not having to output the results anywhere with a slow latency or wait for new inputs from elsewhere. But the app is having to deliver results to the GPU which then renders frames, which takes time. If the GPU is the bottleneck then what is the processor doing while it is waiting? Obviously not pre-rendering future frames, but waiting to synchronise with the results back from the GPU, or get notification that it is clear to send the next set of frame data. So some of the inter-frame time will be idle and waiting on those events, hence the lower CPU utilisation. It's the cross-CPU load (ie. whether 4 out of 4 are fairly equally loaded, or just 1 or 2 at peak load) that shows whether parallel threads are being created and distributed to available cores.