ho scoperto che e' possibile disabilitare la protezione di overvolt e sovracorrente sulle gtx 480.
You can disable OCP via software ( flash the CHL8266 controller with a modified firmware which disables OVP & OCP ) [ you still need to do the MEM OCP mod, this disables the OCP for the GPU core only ]
http://benchzone.com/Downloads/Extreme_Overclocking/nVIDIA/GeForce_GTX_480/CHL8266_No_OCP_Firmware.rar