4DS - Anything but Charting, page-22107

HGST is a wholly-owned subsidiary of WDC. It is where the relevant expertise lies.

HGST/WD have far more to gain here. All they lose is some time consulting, but they get a right of refusal to purchase plus a discounted licence option for as long as the JDA remains in place. Given HGST provided the secret sauce to get 4DS to DRAM speed, while 4DS retains ownership of the IP I'd suggest it has been a symbiotic relationship.

But, the question is whether it should continue once 4DS has a hot little megabit chip in its hands.