S(Ugg... I don't know why BITMAIN has to do this, couldn't they just use a nice big monolithic heatsink, tho did I see that on one of the earlier series S)
Because those monolithic heatsinks will heatsoak and hold heat in well after the miner has stopped hashing. It was a big problem on the Avalon6, you would stop the miner and watch the chip temps go up because the fan spins down to idle and the giant heatsink cant radiate enough heat on its own to cool off properly.