alt Hacker News> Can they double the memory lanes without switching socket?
Sure. Keep the DIMM sockets and add HBM to the CPU package.
Actually probably the best possible architecture. You can choose to have both or only one, backward compatible and future proof.
Yes, it adds another level to the memory hierarchy but that can be fine tuned.
It’s really not that simple, the unpopulated memory slots will cause havoc with signal integrity 4 slot boards already suffer from this.
You are also overestimating how much room there is on the interposer.
As someone with a 9950x3d with direct die cooling setup I can tell you there is no room.