MacPro Mid 2010, issue with RX 580 graphics card

if i am not wrong the only rx 580 card which is not proper for the mac pros is the XFX because of the dual Bios.

copy paste from mac forums :the reply to my answer which rx 580 are work with mac pro is << The consensus is that all except XFX as they sometimes stray from the AMD reference design but having said that . . . their latest RX 580 is a dual BIOS model and so has the much desired 'dual bios' switch which means .. . ( probably won't happen ) that if some genius discovers how to EFI flash an dual bios ) RX 580 then one can safely flash said EFI rom to position 2 on the dual bios switch and if there is a failure . .shut down . . flip the switch to position 1 and you're back in business and then it will be possible to re-flash the original 'SAVED' rom back to the card.>>

i am not the best to answer you but with exactly radeon card have you used ?

i am in search of a card too and i was about to buy pulse and radeon rx 580 ...

When you installed High Sierra with the original graphics card in place did you perform the firmware upgrade.

If not put the original card back in, remove any other deviances from the original hardware profile

and perform the firmware update. make sure your Mac is working, shut down. Re add graphics card d

first and see if it will boot this time with an image. Then if that is successful insert any other pic-cards etc you had one by one, boot ing up each time to see how it goes.