Economically, the United States, the eurozone, the United Kingdom, and Japan are all idling.

A processor capable of simultaneous multithreading has only one execution unit ( core ), but when that execution unit is idling (such as during a cache miss), it uses that execution unit to process a second thread.

And yet we may not realize that in a standard sedan, of all the fuel energy you feed into the car, seven eighths never gets to the wheels it's lost first in the engine, idling at zero miles a gallon, the power train and accessories.