AMD mining is still not dead even if the Bitmain E3 dominate the EThash mining. There are still other profitable coins to mine using AMD GPUs ,if you are a true miner you will not get panic about the release of Bitmain E3, algo switch to the rescue but it will take time to adjust and fine tuning to other algo. AMD GPUs is still more energy efficient compared to NVIDIA, so that's why we can not conclude that AMD mining will be out of the mining scene.
I agree if you think the E3 is less efficient. But F3 will kill AMD mining in ETH.
As far as I know, the F3 miner is still a thing of speculation. No solid proof has been given out except the one video (could be fake).
At this point, I'm of the opinion that if that video "claiming" to be about a F3 Ethereum ASIC was about a real miner, it is more likely to be the next generation Bitmain 14/16nm SCRYPT miner that I anticipate showing up in a few months, probably to be known as the L5 and by one report using 1300 watts.
1500+ Mhash of SCRYPT is a significant improvement over anything current on efficiency (about 3 times the hashrate for 1.5 times the power if that 1300 watt figure is correct), so well in line with what we've seen the 14/16 nm node achieve over 28nm on other algorithms.
That's why I hate china ASIC manufacture.