that's because the the swiftech block does not go directly on the NB. it has to travel through the heatsink assembly first before even reaching the block. and to add on to that, the whole stock assembly is mostly aluminum. only the heatpipes and small part of the base is copper. if you want to properly cool the board, you have to make direct contact with the NB. EK has two blocks that will fit it after you take off the heatsink assembly.