4DS - Anything but Charting, page-30782

You are totally wrong in your statement that memories produce the hottest part in a GPU.
The heat is produced from the thousand of Cores running in parallel that produce the heat. The greater the loading, the more heat that is produced from the transistors switching. Every time the junction of a transistor or diode has a voltage applied to it, it will produce heat as there is resistance to overcome for it to perform it's function. When you take the billions of transistors in the cores of the GPU switching hard out (clocking), you produce a large amount of heat.
If you have an LED panel TV, you will be able to feel the heat coming from the panel as the LED's are switching quickly. The Cores of a GPU are a lot more complex due to the Gate structures within.
The cooling on top end High End with extremely fast clock rates use ammonia liquid cooling with fans to dissipate the heat. The faster the clock rate the more heat that is produced due to the increased rate of switching of the cores.
GDDR memory wrapped within the GPU does not produce the heat!