It is clear now that the next generation flagship AMD graphics card will come under the Radeon R9 380 brand name and we even have the names of the GPUs that will likely be used there – Fiji or Bermuda. However, AMD will surprise fans and competition with a major new technology called HBM or High Bandwidth Memory.
The information comes from Linglan Zhang, who happens to be the System Architect Manager (PMTS) of AMD so we can accept it with a high degree of reliability. The new high-end GPU will likely use 2.5D stacking instead of the expected 3D stacking. This means it will implement two dies that are flipped over and placed on top of an interposer. The interposer has all the wiring which makes the GPU cheaper to make but it requires more die area. Moreover cooling mechanisms can be placed on top of the two dies.
Unfortunately this same preliminary information claims that the new flagship GPU will need 300 watts of power, which is a lot. This means that the chip will likely use 28 nm technology or that it might be built on 20 nm technology but the added HBM memory takes the overall power consumption to 300 watts. We will see what we’ll get later this year but the new Fiji/Bermuda GPU is likely to be a power hungry beast.
As to the HBM memory it will be made by SK Hynix.
Source: Videocardz.com