I have this problem all time:

04.07.2018 13:45:52 CUDA: Device: 1 Thread exited with message: "all CUDA-capable devices are busy or unavailable"
04.07.2018 13:45:52 CUDA: Device: 2 Thread exited with message: "all CUDA-capable devices are busy or unavailable"
04.07.2018 13:45:53 CUDA: Device: 3 Thread exited with message: "all CUDA-capable devices are busy or unavailable"
04.07.2018 13:45:53 CUDA: Device: 4 Thread exited with message: "all CUDA-capable devices are busy or unavailable"
04.07.2018 13:45:53 CUDA: Device: 5 Thread exited with message: "all CUDA-capable devices are busy or unavailable"
04.07.2018 13:45:53 WARNING: Looks like GPU0 are stopped. Restarting...
04.07.2018 13:45:53 INFO: GPU0 are restarted.
04.07.2018 13:45:53 WARNING: Looks like GPU1 are stopped. Restarting...
04.07.2018 13:45:53 INFO: GPU1 are restarted.
04.07.2018 13:45:54 WARNING: Looks like GPU2 are stopped. Restarting...
04.07.2018 13:45:54 INFO: GPU2 are restarted.
04.07.2018 13:45:54 WARNING: Looks like GPU3 are stopped. Restarting...
04.07.2018 13:45:54 INFO: GPU3 are restarted.
04.07.2018 13:45:54 WARNING: Looks like GPU4 are stopped. Restarting...
04.07.2018 13:45:54 INFO: GPU4 are restarted.
04.07.2018 13:45:54 CUDA: Device: 0 Thread exited with message: "all CUDA-capable devices are busy or unavailable"
04.07.2018 13:45:54 WARNING: Looks like GPU5 are stopped. Restarting...
04.07.2018 13:45:54 INFO: GPU5 are restarted.

I have 6x 1070 ti, the OC is ok i think, 65 TDP, 180 core, 550 memory, windows 10.
Thanks for helps.