my rigs keep restarting after few minutes. Some after 5 mins some after 30. Im not sure why this keeps happening.
im using all 1070's with core 100 / 1050 also i tried 150-200 / 1100-1600. No luck
what is your power limit on them? for 1070s I would push around 120-125 with a moderate/heavy OC. Anything less can cause stability problems.
my power limits are all at 125
With your core around 100, 125 may not be enough for the card. Try running 100cc and put it around power level 130-135, if you are doing ETH, it is sometimes better to do negative core since it has very little affect on hash rate and uses a lot more power. My 1070 ETH rig runs -100 cc and between 1200-1275 mem.
If that does not solve the problem, I would check to make sure everything is connected properly, I had one time one of my riser USB was not in all the way and had intermittent connection and was causing my problems.