As I understand code optimization failed, so there is only one way left - to OC core. 
Looks like it.Show plz result with default miner and with your miner, and core setting. But not dashboard, raw hashing more interesting.
I did a few posts ago.(Scroll back) on the 1070ti and the 750ti Same clocks and settings.
1070ti:
ccminer 2.2.2: 2.1 MHASH
ccminer sp-mod 2.42MHASH
750ti:
ccminer 2.2.2: 220 MHASH
ccminer sp-mod 440 MHASH