Try to use other miner like T-rex and I suggest you switch to HiveOS and use Ether pill instead to Improve the hashrate of this card.
Or if you are in windows OS you can try to use ether pill to improve your hashrate.
Comments:
1) You should get 39 to 41 with the 1080
ti card at maximum efficiency.
2) there are 3 pill options, they are all about the same:
a) ogodanETHenlargementpill.exe (Be careful with this one because there are virus infected versions)
b) T-REX Use the
-mt 5 setting use the latest 0.19 version
c) PHX 5.5D MUST USE the -straps 5 option
3a) setup: 50/100/-501 to 54/125/-501 As far as I know this is the best efficiency settings (about 150W per card)
3b) You can run this card full out (100/0/0) and reach 70 BUT the card runs very very
hot. This is the Scandinavian option

where you have cheap hydro power and it's zero C in the summer. Requires serious thermal engineering on the users part.
4) Use a large swap file.
5) This card is alo has a lot of flexibility and can decently mine a lot of coins.