Microsoft claims to have wholly redesigned the passive cooling, to allow both the Core m3 and Core i5 models to run 100% fanless, instead of just the m3 model like last year.

It looks like most of the improvement came from shaping the heat sink like a certain Zerg unit.

With the heat sink out of the way, we still have to remove a couple of components before the motherboard is free. It's trapped under one speaker and a sensor/camera bezel.