thanks all for the reply guys. really appreciated your advise now i'm using 5x 1070 and 1x 1080ti just basically added 4x 1070 lol. anyway i do have new concerns can mine using window 7? and what best application I can use for these cards? 
Sure, win7 is ok for mining rig. There a lot of miners (software) for different coins, you should find info about the best ROI coin for GPU you have and the search for suitable miner for that coin. Just do research, read the forum.just now i upgraded to win10 due i try to mine using win7 and my zpool auto close. anyway do i need to install cuda? i already update my nvidia's card