If you look a bit closer you can see that a part of these grooves have a wave-like shape instead of just being dead straight. This peculiar shape raises the turbulence of the water, entering the waterblock, which makes the water absorb more heat thus improving overall performance of the block. Last but not least there are about 45 very shallow holes on the bottom on the inside of the block. These holes are actually called Heat Voids and add to raising the turbulence of the water, every way of improving the block's performance has really been employed by Danger Den.



Link: Crazymodders