Can someone help with a very good Overclock setting?

I have 6 GTX 1080Ti GPU  running on Simplemining OS. However I have been trying to get good hash rate on x17 (mining Verge, the only Altcoin for it on Zpool).

I have tried different overclocking settings but my hashrate wouldnt just pass 13MHs per card and only giving me between 56- 72 Mhs mining using x17 Algo.

It is kind of weird situation because same cards exceed 5800Mhs on other algo. What am I doing wrong guys?? I need a better hashrate.

Please I need your kind contribution here.

Regards.