Originally Posted by EightDee8D
980ti vs furyx, i believe amd had less margin because furyx had hbm and clc, compared to normal cooler and gddr5 on 980ti.
AMD gets margin with Fiji on the entire assembly, rather than just the GPU, so they are probably making more per card than normal.
On another front, I think people are misjudging what a 4096SP GCN4 card would do with 512GB/s+ bandwidth.
Polaris 10 is heavily bottlenecked by its memory bandwidth. I overclocked the memory on my RX 480 and received linear performance gains until the memory errors took over at 2225Mhz+:
That's 2304 SPs and 32 ROPs being fed with 8 GDDR5 chips.
77% more SPs and double the ROPs can be fed with just TWO (2) HBM2 modules, and a 2048-bit bus... or with a 320-bit GDDR5x bus and 7Ghz modules, if my math is right
HBM2 is more expensive, but the ability to only use two modules per GPU while having more simple PCBs - and the aforementioned net profit benefits for AMD - make this a very workable solution... possibly even better than a 320 or larger GDDR5x bus... not to mention AMD already has the tech and supply chain for HBM... and "kind of" created it
Not quite sure when it will be available for use in a mass-produced product, though...
Add 20% for the faster clock-speeds you would expect from Vega, 15% or so unleashed from GCN4 (when it's not memory bottlenecked) and you're closing in on 40% faster than Fury X. That's already quite close to the 1080's performance level. If AMD has done more improvements to help scaling or utilization, then they will likely be head to head with 1080 using a 4096SP Vega.
The next thing is the power usage - it'll not be particularly thirsty. P10 @ 1.2Ghz is 110W TDP... due to factory over-volting, mostly. 77% more SPs, double the ROPs, but swap out the memory controllers for HBM controllers and you end up with about a 175~200W TDP GPU. With the two HBM2 modules only using single-digit watts each, we'll just call it 10W for good measure. So, 185W to 210W. VRMs are only 85% efficient, ish, which moves us into the 225W to 250W region for the whole card, while providing 1080 levels of performance. Assuming AMD doesn't do better with the voltage and doesn't make any other efficiency improvements. That's pretty decent, IMHO.