So i wanna sell my pc but my vga is unstable with the default bios, the hynix memory is really unstable at 1600mhz, i'm trying to change it to 1500mhz by hex editing it. But it's my first time hex editing a bios and i'm not having a good moment lol. I'm tired of going to my onboard just because i broke my bios, can someone give me a light? https://www.techpowerup.com/vgabios/141558/xfx-hd7790-1024-130322 This is by default 40 06, which i think it's the 1600mhz from the memory, i got there (E690) by comparing 2 bioses, it needs to work but everytime i flash my gpu "dies".
7790 is the only card in the 7000 series that isn't supported by vbe7 https://www.techpowerup.com/forums/threads/vbe7-vbios-editor-for-radeon-hd-7000-series-cards.189089/
You are probably getting the wrong location by doing this. Maybe this link will help you: http://www.overclock.net/t/1561372/hawaii-bios-editing-290-290x-295x2-390-390x I used atomdis once to fix an hd4350 that had a broken powerplay section (impossible to flash it with another bios cause every single bios that i found working for it was swaping vga and dvi connector resulting in dvi connector not working, vga was working). At least in the case of my hd4350 case the PowerPlay section had the freq if I remember right. Without atomdis I was assuming that PowerPlay section ended sooner than it was in reality and this was exactly the reason I was failing to fix, the stuff needed to be changed was in the area that I was assuming it's something else. The location of each bios section it's not in the same place on 2 distinct bioses. ( Let's say you compared 2 bioses for gpu1 one original one with mem freq edited, you will get a location. That location will not work for gpu2 unless gpu2 is a clone of gpu1 (gpu1 and gpu2 need to use the exact same bios else that address is wrong in most cases. using atomdis on several bioses for same gpu model from several venders will show you that the addresses for each bios section don't really match.)). You can also read this topic: http://forums.guru3d.com/showthread.php?t=400050 I don't know much about GCN bios structure this is why I suggested the 2 topics (GCN bios structure is far more complex compere to TeraScale, in your case you have an UEFI bios section that probably has it's own clocks...). You probably have to fix a checksum somewhere, else the bios will probably not load cause it fails the bios checksum (when you try to flash the bios with the wrong checksum it should complain about the wrong checksum, I think you can bypass the flash tool checksum part). The mem freq will show up in a couple of places for sure (in theory it can be only in 1 single place but i kinda doubt it). If it's unstable at 1600 you need to lower them all.
why dont you try mod it to 260x? I did it with Sapphire 7790 1GB and got 260X, if you know how to restore bad bios flash you can start looking for similar 260X bios.