Hello
@ckychris
In order to design a heatsink there is several parameters that need to be optimized. In the case of "The First" fins pitch and thickness are optimized for natural convection (0% fan) and regarding the global volume we wanted.
In that case, increasing the wolume by 3 won't result in having 3 times more power. After some time all the air is hot and fins can't echange heat anymore. Please see a run made on "The First" heatsink.
But for sure you will have more power !! Maybe 2 times !!??...
So why I'm not considering it for an ATX extreme solution ? Because you need to tranfert heat from the component to the fins.
Commonly for non water solution as in "The First" we use heat pipes. They have limitations regarding length of transporation.
As you certainly know they need a good balance between power, length, shape & gravity.
--> In our case (6mm heat pipes) it would be really difficult to have 200mm more...
Don't worry, we have other ideas