unspecific failure after mining for a while
I have three 1060 6G NVIDIA cards to mining xmr using xmrig 2.8.3, but there always show unspecific failure after mining for a while.
![rigerror](https://user-images.githubusercontent.com/5423698/47557488-60827a00-d943-11e8-94c1-633654c67fcf.PNG)
