I have a pair of Powerrcolor Red Devil RX470 cards. They are not identical - one has Samsung memory, the other is Hynix. I made backups of the original BIOS from each, using both GPU-Z and AtiWinFlash. I have the originals carefully named and saved in a safe location. I used Polaris Bios Editor to modify the memory timings on each, trying to get a little more ETH mining hashrate from them. It seemed to work, but the rate gain isn't really worth it. I'm "stuck" on Radeon Crimson 16.11.5, since the driver signature check built into later Radeon drivers prevents them from loading. I'd like to go back and restore my original BIOS, but it doesn't seem possible. I've used AtiWinFlash to put the .rom file back in, being careful to keep the correct version (Samsung/Hynix) with each card. However, if I extract the BIOS a second time immediately after flashing in the original, it doesn't match during a binary file compare! C:\Util\AWF>fc /b before.rom after.rom Comparing files before.rom and after.rom 00000021: B2 B4 00000267: D2 D0 In other words, the BIOS that I just flashed moments ago does not match itself. The file that I flash into the card doesn't match what I read right back out. I still can't get the current Radeon releases to recognize these cards as having official, signed BIOSes. Any hints as to what I'm doing wrong?