• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

AMDVBFlash and GPU-Z produce GPU firmware backups of different filesizes


New Member
Jan 31, 2021
4 (0.01/day)
I noticed that when I do a GPU BIOS backup from GPU-Z or save the BIOS to a file using amdvbflash on FreeDOS that the file sizes don't match. GPU-Z produces a file of around half a MBs size (which is as big as files in the vgabios collection for similar cards are), while amdvbflash creates a size a full MB big.
What is the technical reason for this? The verify utility of amdvbflash gives the same checksum for the card and for the file created with GPU-Z on Windows, so what is the difference?
Which one should be flashed, if wanting to go back to stock?


Staff member
May 14, 2004
25,166 (3.68/day)
Processor Core i7-8700K
Memory 32 GB
Video Card(s) RTX 3080
Display(s) 30" 2560x1600 + 19" 1280x1024
Software Windows 10 64-bit
There's a lot of zero bytes at the end, which are useless. There's no difference, both work perfectly fine and will return your card to the same state

Feel free to compare with hex editor