GPU Performance Gauges

Are there any programs like the Performance Meter under Windows Task Manager but for video cards?

I'm not talking about FPS, etc. performance benchmarks. I'd like to see percentage video memory and GPU usage, etc.

% GPU usage is almost always 100%. The GPU kicks out as many frames per second as the code programming the frames allows.

Memory on the other hand can go from 0 to 100% - don't think there are any real-time monitors of it though.