Hi,
 
I read that my efi boot mode problems are due to a combination of mainboard bios and vbios gop compatibility bugs. After searching on the internet people with MSI cards and the same black screen bios lockup issues when setting to 'EFI Boot' were able to fix it by updating the gop rom on the video card from the manufacturer. As EVGA has stated that its vbios is perfect even though its not 100% compatible with older boards(like my p8z68 deluxe) I was wondering if I can flash MSI gop vbios onto the EVGA 780 SC cards I own as I would like to setup a gpt boot drive in efi mode?
 
Thanks.
 

As I have two GTX 780 cards with the same model and sku numbers would it be safe to flash the firmware from card b on to card a being that one firmware is newer than the other?
 
Thanks
 

Well being that its sunday and they are closed I went ahead and flashed with latest vbios versions I could find from Techpowerup's vbios library and noticed that even though I thought I had identical cards one is a GK100 card and the other is a GK100B card with each having a corresponding and different vbios verified using a hex editor and checking the hardware ids. The flash went smoothly and the firmwares are a few months newer than before. Interesting that the GK100B I found out is a 780 rev 2 gpu and has a much better asic score. So I pulled each card out and swapped them so that the newer GK100B card would be the primary card on the motherboard. Still didn't solve my motherboard's refusal to run in 'EFI Boot' mode. Locked up as always not letting me go into bios with out a cmos reset. Oh well. Legacy boot mode it is..
 
Thanks.
 
Edit: The hardware ids are actually 10EC-2784 and 10EC-0784 for the GK100B.