I guess we're on opposite ends of this.Actually its well known that 16/14nm yields for die sizes above 200 sq mm are really bad. In fact only TSMC 16FF+ is going to be feasible for 300+ sq mm GPUs in terms of yields. But TSMC will be capacity constrained as demand far outstrips supply at TSMC 16FF+. Moreover TSMC will give first priority for Apple A9, A9X and A10/A10X (Q3 2016 release) . Nvidia and AMD are better served by using 16FF+ for selling high performance USD 300+ GPUs. AMD's choice to thus go with two GPU dies - a 110 - 120 sq mm low power GPU die fabbed at GF 14LPP and a high performance 300 sq mm GPU die fabbed at TSMC 16FF+ makes sense.
My guess is the the low power GPU specs will be a
R7 470 - 768 sp,
R7 470X - 1024 sp, 1 geoometry engine, 1 raster engine, 32 ROP, 128 bit memory bus 8 Ghz GDDR5
The performance will be on par with GTX 960 for the fully enabled SKU and GTX 950 for the salvage SKU.
the high performance GPU using HBM2 will power 4 SKUs as I expect yields to be really bad for 300 sqmm GPUs in 2016. I think there is going to be heavily salvaged SKUs in 2016 to fill the product stack. We will see a dedicated mid range chip in 2017 once yields are much better.
R9 490X - 4096 sp, 4 geometry engines, 4 raster engines, 128 ROPs, 2048 bit HBM2 , 512 GB/s, 8 GB.
R9 490 - 3072 sp, 4 geometry engines, 4 raster engines, 128 ROPs, 2048 bit HBM2 , 512 GB/s, 8 GB.
R9 480x - 2048 sp, 2 geometry engines, 2 raster engines, 64 ROPs, 1024 bit HBM2, 256 GB/s, 4 GB.
R9 480 - 1792 sp, 2 geometry engines, 2 raster engines, 64 ROPs, 1024 bit HBM2, 256 GB/s, 4 GB.
AMD's approach makes a lot of sense as they use GF 14LPP to serve the high volume GPU market as AMD has a WSA to meet. GF will be able to yield a 110-120 sq mm die reasonably well enough and AMD can try and push as much volume as possible from GF 14LPP. TSMC 16FF+ will be used for the bleeding edge GPUs of 2016.
I expect 4th gen GCN to have significant improvements in perf/sp and thus I think we can expect a 25-30% faster flagship R9 490X GPU compared to Fury X. I think Nvidia will come out with a faster GPU as Maxwell already has impressive perf/cc and Pascal should bring more. I think the Nvidia GPU will be 10% faster than AMD's flagship GPU.
You actually see <50% shaders as a harvested die? Wow. I would never have considered that.
My belief is that we are still mentally trapped in the old world of monolithic designs. The use of interposers radically change the old design limits. Interposers are NOT PCBs.
With your above example, the 490X is a bit better than FuryX, maybe 20-25% performance wise, not power.
Two 200-225mm^2 die should allow a 490X to be 80 % better than FuryX AND maybe cost the same as a 300mm^2 one, if your prediction of terrible yields as you approach 300mm^2 is true.
You will need an interposer and HBM in both cases, and the present one in Fury is big enough for (2) 225 GPU die.
IF AMD wants to regain market share, they can't dance with Nvidia. They have to be clear in front. Raja must know this.
Also, if you see 300mm^2 as being poor yielding at first, why are so many Nvidia fans expecting a big GP100 early?
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