Like before any new major launch, leaks appear everywhere on the Net. Today, here are the specs of the Tahiti based graphics card, the new Radeon HD 7970:
- GPU: Tahiti XT @ 925MHz, 28nm, GCN architecture (Graphics Core Next, see HERE for some details).
- Shader processors: 2048
Compute units: 32 (64 shader processors per compute unit – more information about compute units HERE) - Texture units: 128
- ROPs / Z-stencil: 32 / 128
- Memory: 3GB GDDR5, 384-bit, 5500MHz
- Power connectors: 6-pin + 8-pin
- TDP: less than 300W
(source) | (via)
so they canceled using xdr2 vram.
They never intented to use XDR2, it was just a silly rumour.
PS. The clocks should be 880mhz and TDP around 200W.