Just got a 1080ti 2 days ago and I believe it is underperforming, I've watched videos on it with close to the same setup as me in GTA V and they get a lot better fps than I do. People get better fps than me in 4k and I'm in 1080p
I left MSI hardware monitor logs in the attachment for help
http://www.userbenchmark.com/UserRun/8527066
GTA is at all max settings except for it's at 4xmsaa and no extended distance scaling 1080p
Black ops 3 is at complete max settings all around 1080p (card max at around 30-40% usage)
Let me know if anyone needs any more information and I will try to get it to you
black ops 3 hardware monitor.hml
GTA V hardware monitor.hml