I have tested 3 apps, BitCrack 625MKeys/s, VanitySearch-BitCrack 1024MKeys/s but the problem is it gets hang multiple times in a day and forced to restart my PC, and KeyHunt-Cuda 945MKeys/s with these settings (KeyHunt-Cuda.exe -t 0 -g --gpui 0 --gpux 950,256 -m address --coin BTC...)
Does not hang for me running days. Something is wrong with your system.
Could be the high load, maybe the power supply can't handle it or just the general overheating. I would try to run it with opened case maybe or add some extra air flow.