Originally Posted by guttheslayer
You do not understand the term performance per watt. It is the performance given for the fixed amount of wattage. That 2X PPW is the best case senarios I agree, but I can assure you the 360mm^2 chip is not fake, and using 7nm mean there is so much transistors that is pack inside. You cant lie with Physics.
I wont find it out of any impossibility realm for Vega 20 to comes pack with 128 CUs. But the functional one could be lower like 112 or even 96 CUs (due to yield issue).
I know what performance per watt is.
What you don't realize it is a scalable term.
2x the performance while using the same wattage is 2x performance per watt while similarly, having 33.33%extra performance while using 66.6% of the power is also 2x performance per watt. This is because mathematically they are the same.
Say a GPU gets 100 fps with first gen technology, using 100 watts. Lets say 2nd generation, they get 2x performance per watt. This could mean 200fps for 100watts or 133fps for 66.6 watts and they would be mathematically identical in terms of performance per watt.
Where the first gen of the technology was 100fps/100watts = 1fps/1watt
2nd gen both represent a 2x increase in performance per watt and are thus equivalent. When we normalize it, we see they produce the same values.
I.e 200fps/100 watts = 2fps/watt. 133.3/66.6 watt = 2fps/watt.
If you look at AMD end notes, AMD gets their inflated performance per watt figures by comparing it to their least efficient architectures. In polaris case, they compared it to hawaii. Polaris definitely does not have 2x the performance of hawaii but approaches 2x the performance per watt because it gets similar performance for half the wattage.
The thing is if AMD could get 2x the performance for the same wattage, they would have said 100% increase in performance and 2x increase in performance per watt. This is not the case.
Instead AMD is stating that their next product has 2x the performance per watt or 35% better performance. Not both at the same time.