Then I would consider that the problem is the Viewsonic | Monitor Driver | MacOS or that perhaps you need a new 980 Mac flash. You should be able to flash it using the latest version of nvflash Estimated Reading Time: 11 mins.
(Soldering not required on EVGA's, some BFG and XFX)-8800GT EFI64 Can flash: Most 8800GT's and 8800GTS. Hello together, I want to flash nVidia cards with a MacBootScreen It is also possible to write an EFI app to render on eGPU screens.