hi guys just wanted to update you on my experiments..
Removing the smd at the bottom right (the one only in the row) I unlocked the 8 giga via pcb and I reflash the stock bios...
Apparently nothing has changed .. and unfortunately, as I already thought, the problem of low hash rate on some cards is not solved ..
I will check how it goes in these days and then at most I modify all the cards (just 5

)
My stock bios, as you can see in the picture, is 86.04.7A.00.02 ... does anyone have if exist an updated stock bios for Zotac?
https://imgur.com/a/TWNmleL