I've read through the forums and found what seemed like conflicting answers regarding this topic; therefore, if someone has answered this in the past, I apologize. mac pro 1,1, 2x Dual Core Xeons, 8GB RAM, 7300GT. I would like to flash the onboard EFI to 64-bit. Some reports seem to indicate that this is possible and will cause the Mac Pro to identify as a 2,1, while others say that the EFI cannot be flashed at all. Ultimately, I would like to put two quad core Xeons in place of the duals. Is it possible to upgrade to 64-bit EFI? Thanks in advance.