[edit: I think I'm wrong!] I'm pretty sure this is HBM (High Bandwidth Memory) on the same substrate: https://en.wikipedia.org/wiki/High_Bandwidth_Memory https:

[edit: I think I'm wrong!] I'm pretty sure this is HBM (High Bandwidth Memory) on the same substrate: https://en.wikipedia.org/wiki/High_Bandwidth_Memory https://en.wikipedia.org/wiki/High_Bandwidth_Memory There are some other explainers out there that go into more detail, but Nvidia is also doing this with Grace Hopper (I think?), and Apple with their M-series chips. Update: It looks like it's just DDR5 ("custom DDR5-4400 DRAM") in this case.