Watercooling 201: The Waterblock
 

It's the same misconception as air cooling – a heatsink doesn't actually cool the chip. It simply provides a greater surface area for the heat to spread over. Since there's more metal to heat up, there's less heat in each molecule of metal – so it seems like it's cooling. The real definition of cooling is the removal of heat from the system – no heat is being removed here, just simply spread out. Instead, it's the fluid—be it air or water—that actually does the cooling.

This probably seems pedantic – the block cools, or the block spreads the heat and thus lowers temperature. It may seem the same, but it's not – it radically changes how we need to look at water blocks. We can distil everything above down to one basic statement:

A block's function is not to cool your CPU – it's to provide the most contact with water molecules as possible

http://www.bit-tech.net/modding/2008..._waterblocks/1

Finally, I hope people who are making homebrew coolers now do understand what I was trying to explain them few months back ;)