How much of a GPU's electrical usage is probably turned into a increase in air temperature?
My numbers might not be exactly accurate, but I would say that about

99.99% of the energy that enters the GPU, and even CPU is converted into heat.

The other .01%, is the actual signal out of the GPU to your display.

The job of the GPU is to take in a lot of data, and process it, requiring a lot of calculations. These calculations consume energy, producing heat, and eventually a result.



Now it is important to note that while this says that it is a 375W card, it will not be drawing 375W the entire time it is in operation. Just like your CPU, your GPU will only do as much as you need it to, and may step down &lt;100W.

Simply browsing around your windows desktop, the card it doing next to nothing, and will draw next to nothing; but launch Crysis, and your frequency mill max out and the card will start drawing its maximum rating.