..So you have dual Nvidia's but are disabling SLI to play? Or what's the story there? Possibly doesn't matter..
Well, there's a couple of things with this.
At the OP, I mean no offense, but that dual-GPU setup isn't great.
SLI will only run at the speed of the 1070. Two 1070's in SLI will perform fairly closely to a 1080, and you have a 1080 Ti. Only real reason to run two cards like that is to support a butload of monitors. Based on the data, you have one.
If you had a 1070Ti, that might be different, but only in games that support SLI. (Note to Cadamier, 7DTD does not support SLI.)
With just a 1070,
if the game supports SLI, and
IF scaling is around 80%, it
might be smidge faster than the 1080TI. We're talking maybe a grand total of 5FPS here at best, and that's in rare conditions.
Again, I mean no offense.
Insider preview is most likely the culprit. It's been wreaking havoc on games galore for a couple of weeks now. A client log from a crash would be useful though.