First time mining. Trying to fine tune but need some advice.

So currently I'm running a single RTX 2070 (not a super) when I'm away from computer at 75% Power limit, -50 Core and +850 mem. On the trex miner I am getting 15.65 MH/s. If I go up to 900 mem it crashes. Mind you when I was setting it up I ran everything for a few minutes just to see if it I had set it up correctly, and my MH/s was between 34-40 (which after reading now seems to be what I'm looking for.) I just need some help getting there from all the homies out there with a 2070. Thanks in advance guys. Let me know if screen shots would help.