More and more rumors start to surface on the  Radeon R9 380X using HBA memory. And yeah, we know the name now as well, R9 380X as in LinkedIN Ilana Shternshain, an AMD ASIC physical design engineer named this product. 

Iiana "responsible for full-chip timing methodology and closure for AMD's most exciting chips." apparently has been working on the PlayStation 4's SoC, the Radeon R9 290X discrete GPU,  .... and the R9 380X, which is described as the "largest in 'King of the hill' line of products."

The second clue is that AMD system architect manager Linglan Zhang says he was involved in developing "the world’s first 300W 2.5D discrete GPU SOC using stacked die High Bandwidth Memory and silicon interposer." Well, that's cool on your resume alright, but a little silly to post on your linked in pages.

Linglan Zhang already removed the info from his linked-in page though. 

AMD already started sampling first generation HBM with their graphics cards according to rumors. This stacked layer memory would be merged on the PCB just like the regular memory chips but would deliver high performance  (HBM = High Bandwidth Memory). AMD is expected to introduce the R9 380X early this year, but hello ... 300 Watt ?