6900K is an older gen architecture though, would have been more noteworthy to compare it to any ~Lake series architecture IMO. I'm sure once the 9900K hits and we have direct comparisons to a 2700X everything will become clear.
This is true, but it's the best, most recent data I could find. If you have a more data, I'd be happy to look through it as well. It also correlates with Stilt's data as well. When you take out the outliers, he showed 3% higher relative improvement for AMD and hardwarecanucks showed 5%. Not exactly the same, but pretty close and it will obviously change depending on the test suite used.
I'm also fairly sure the Skylake based HT enabled CPUs like the 8700K show very little negative scaling from HT in gaming
Probably true, but again, I have no data on that.
in any case including gaming numbers into an 'SMT yield' analysis is somewhat ingenious because Intel CPUs are actually strongest in gaming to begin with and is the one area where AMDs core/thread advantage generally doesn't translate to better performance.
I don't think anyone included gaming numbers when presenting SMT yield, or at least, I didn't. If I had data from 4 core / 8 thread processors I might as that might actually yield interesting data. As it is, there's maybe one or two games out there that will scale beyond 8 cores, so using games when comparing SMT on / off with a 1700x and 6900k would be pointless, outside of the observation which I mentioned.
It's like saying Vega 64 gains a bit more from DX12 than a 1080 Ti does, but then not mentioning the 1080 Ti is actually 20% faster still.
No it's not, because you don't care about absolute performance when discussing SMT uplift, you're just calculating SMT uplift, that's all. Obviously you don't make any kind of performance or buying conclusion based on that one metric, it's just an interesting point of comparison between two architectures.