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YES, you must unzip the (.ROM) file and place it on a non-partitioned FAT32 Flash Drive.
There are (2) safe methods to updated your Sabertooth X79:
1. ASUS EZ Flash 2 - http://www.tomshardware.com/forum/289507-30-what-flash
2. USB BIOS Flashback - http://event.asus.com/2012/mb/USB_BIOS_Flashback_GUIDE/
If using the 'USB BIOS Flashback' method then correct you must rename the (.ROM) file = SABERX79.ROM
However, if you're having problems when you're (IN) the BIOS then you need to resolve that issue first; Clear CMOS (if you don't have a RAID array)
use the Jumper method, unplug the PSU first for 5 minutes to allow it to discharge then watch this video -> http://www.youtube.com/watch?v=rdHH9KrceR0
afterwards go into the BIOS and press (F5) to Load Optimized Defaults.
I have that exact MOBO so it's easy to help you here.