Yeah sparks i don't put in doubt.
One day, I saw very good the little sparks in one of my dead gpus.
When i said this issue to Sapphire forum, a mod insinuated me that i must have a quality hardware above all the psu.
And I said her that the gpu showed me sparks because i had a bad hardware such as a mobo of 200 and a Platinum PSU (Fractal Design Newton R3 1000w)

and that if I had a Diamond PSU with 110% eficiency

i'm sure that i wouldn't see any spark. Sapphire, Sapphire...