MSI GTX 1080 Gaming X
38.5MH/s
Power +65
Core +150
Memory +500
and it is very stable
40.9MH/s
Not stable
Power +80
Core +150
Memory +750
I think that around +600 memory is the upper limit which will be stable. Then again, it depends on the card, I'm using EVGA's FTW3 edition.