> It is DRAM that is on the same die as the cores,

From the article, it was actually a separate die/chiplets,

> Broadwell implemented its L4 cache on a separate 77mm2 die, creating a chiplet configuration. This cache die was codenamed “Crystal Well”, and was fabricated using the older 22nm process.

A lot of interesting details in article about how widely different this dram is, made to go fast fast fast. Fun read.

I'd really wanted a system with Crystal Well, seemed so cool. A lot of macs seemed to have the Intel Iris Pro models that had it. But general adoption in the PC market was - I feel - quite poor.