Hashrate and GPU settings

Hi,

I have mining rig with 4 ZOTAC GeForce GTX 1070 Ti AMP! Extreme Edition 8192 MB GDDR5 graphic cards.

GPU settings: gpu clock +200, memory clock +800, power 75%
One cards is producing arounf 500 sol/s. Is this enough? Is it possible to boost performance?

Second thing that I would like to know is if it is possbile to stabilize effective Hashrate?
Current hashrate is visible in attachment

BR, Nejc

I Have 3 GPU 1070 TI Titanium and 2 gaming x

Clock +200
memory clock +659
power 90%
530 sols/s stable
PS : Titanium better cuz Temp on it always 60°
But gaming x always 67°

I Have 6 EVGA 1070 TI FTW2

Power 70%
Clock +200
Memory Clock +700
Fan 85
530 sols/s stable
Avg Temp 60°

I ave EVGA GeForce GTX 1050 Ti SC I need the stats for this please.

1050 ti 170-180 sol/s