High bandwidth memory (HBM) is DRAM built as a tower. Eight, twelve or sixteen memory dies sit on top of a logic base die, wired together vertically, and the whole stack is placed a few millimetres from a GPU or AI accelerator inside the same package. The reason is bandwidth. One HBM4 stack moves at least 2 terabytes per second, more than three times what a 12-channel DDR5-6400 server socket manages (about 614 GB/s).

A laptop review is not usually a memory-cycle datapoint. This one is. The Framework Laptop 13 Pro drew strong marks for performance, build quality, and keyboard, and was marked down on a single dimension — it is expensive, and the review attributes that expense to high RAM prices. That sentence is the cleanest publicly visible evidence to date that high-bandwidth memory wafer allocation has stopped being a datacenter accounting problem and started setting bills of materials on consumer hardware.