miner software optimization might get 3090 to 150mhs...hopefully 
No, Eth is memory bound, 3080 and 3090 have the same memory type and speed so the minor difference we will see would be due to 320 vs 384bit bus width. And this isnt on-die HBM, dont expect 90+ on anything.
1080 is 35mhs
1080ti is 50mhs
that's 42.8% difference between 1080 and 1080ti, both gddr5x
3080 is 100mhs (there is a post that says 115mhs at 300w) if you do the math of adding 42% of 3080 to 100mhs that's 142mhs.
now nvidia says 3090 as titan like(they phased out titan, this is the new titan), if 3080ti is not released yet, then 3090 is better than 3080ti
if 3090 is better than 3080ti, then 150mhs is not impossible.
XD you cannot add 42% and say "yes thats the hashrate" XD and where is a 43% difference in eth mining between 1080 and 1080ti?
And a screenshot say nothing. Wait i make a screenshot with 2000mh hashrate for the 3070, you believe this?
you will see, 3080 nothing more than 70mh.
In the past, much people say AMD RX5700 will reach 70 or 80 mh, but what is the fact?