TeutonJon78 wrote:
That's kind of why I asked. The uncompressed flash sizes are the full chip size. So it should literally be writing every bit anyway, so I don't see how one method would be different than the others. Maybe the flashback method clears out some UEFI variable or something, but loading the optimized defaults should essentially do the same thing.
And it's not like they advertise that on all the various motherboard models either. And in fact all it says on the listings is you need to rename the file if you are using flashback, not that you need to use flashback. It's probably the same as people who thought you need to factory reset a phone 3 times when you install a 3rd party ROM for some reason -- like it would actually clear anything different.
Actually there are several parts of the Flash ROM that are NOT flashed by default. Frequently the boot code and ACPI tables are not, for example. It has always been this way back to the Intel Pentium/AMD K6 motherboard days. Back in the day, there were special command line switches you would use with the BIOS flasher to force program those normally ignored regions.
And back in the day, there were valid reasons for things to be this way: There was no such thing as "flashback." Heck, Gigabyte's "Dual BIOS" was new thing and a big deal when they came out with it during the Dark Ages. So the boot block of the BIOS was frequently not flashed so that in the event of a flash failure, there was at least a chance that you could get to a DOS prompt and run the flasher again. I had a mainboard once where I had a flash failure rendering that board dead. I worked in a shop, so I had a few identical boards to work with. I had to hot swap the BIOS chips between the boards (they tended to be socketed at the time) on the booted board, and I was able to successfully flash the failed chip in the working board.
