Hello guys i want to ask you about my problem. I have upgraded my old gigabyte hd7850 to the xfx rx580 8gb black edition.
When and only i have uefi boot enabled (csm disabled) weird colors on a box appear before boot( Video link https://www.youtube.com/watch?v=HZB4YiP3YhQ&feature=youtu.be ).
The GPU works fine and nothing else is the problem.
Tried updating gop to 1.69 but nothing changed.
MOBO is updated to the latest modules.
I have seen a similar problem with only 3 green lines with 2 others pc with z77+1060 and z68+1060.
Note that this card with a new b450 mobo doesn't do the problem.

Bottom line i think it has something to do with the xfx vbios not being fully compatible with my old mobo
Anyone has any idea for a fix?(like flashing another rx580 bios?)
THanks guys
Mobo bios + Gpu bios uploaded.

EDIT by Fernando: Title customized regarding the letter sizes

You need new vBIOS with updated GOP, which I'm not sure if you can flash mod vBIOS on RX 580 cards? If you can look around and see mod vBIOS being flashed to this series cards and it's OK, then I can update GOP for you if you don't know how
Ahh! Sorry, I didn't see until later you already did this.. Are you on latest motherboard BIOS? If yes, maybe nothing you can do until they update it, or you'll have to leave CSM enabled

yeah i am on the latest motherboard bios. Its not really a problem,just an annoyance.
I will try flashing vbios from a different brand to the gpu since it has dual bios to see if its the rx580 or the xfx problem.
In the motherboard bios there isnt any modules that could affect this?
THanks for your help

I have made some progress. I have found that the rx 580 sapphire pulse rx580 8gb bios doesn't have this problem. What i want now is to make clocks ,voltage ...etc identical to my bios from xfx. Can anyone help me with this?
By the way i have found a guy with the same problem here: https://www.techpowerup.com/forums/threa...csm-bug.242705/

Bump.... Anyone knows any tool to mod sapphire amd bios clocks and voltages to match my xfx bios?

Hi had the same problem as you, only with this video card. Do as it is written in this thread and get rid of this annoyance. My problem is now gone.