MSI GTX 1080 Ti Gaming X 24 MH/s with ccminer 2.2.4
i'm using 2 MSI GTX 1080TI Armor each card reach 28-29MH/s. i think ur 1080TI can get 30MH/s.
Can You describe your settings ?
i'm using alexis78, then i set the power limit 76, temp limit 76, core clock +163, memory clock +33, and installed newest nvidia driver. i hope that might help u. cheers