I thought this was going to mean each stack was able to directly talk to the controller, since all stacks are resting on an interposer thing. But actually there is still a logic controller slice at the bottom of the stack, not at a right angle to the stack.
Instead of HBM microbumps between layers there is a more compact/dense TSV ("fusion bonded via-in-one") system. Intel once more showing their strong chiplet packing prowess! The claim is that thermals are still much better somehow, in spite of volumetric cell density increasing (from thinner layers). The demo has 8+1 dram+controller layers.
Get perpendicular: https://www.dailymotion.com/video/x62mja
Every time the recipient hypes the shit out of it, of course.