Permabanned
The problem with that is AMD set the voltages for a reason.
And you can also under volte Turing and get a good reduction in power
https://www.reddit.com/r/nvidia/comments/9idtco/rtx_2080_downvolt_the_easy_way/
I don;t think such comparisons are valid though, the average user is not going to be tweaking like that and there is no guarnatee that lower voltages would work.
With 14nm Vega there was a lot of room when it came to tweaking I thought that might be because there was a wide variance going from chip to chip & they were playing it safe leaving it down to the user to find it's limitations after all they are meant to be enthusiast cards rather than mainstream cardss, The same is true for the V7.