High sierra with ati radeon hd 5870 not working

[Iro22]

Hello
I need help when i replace my old gpu with a ati radeon hd 5870 in my mac early 2008 3.1 it boots in and then more then half way it stops an then the screen goes white and after 10 sec of goes black for 1 sec en then it repeats. I have a quad core 2.8 ghz and 6 DDR2 800mz ram with high sierra on an ssd
I hope somebody can help my

 

[KeesMacPro]

Hi

What happens at ~ 2/3 of the booting process is that the OS loads the GPU drivers and thats when your screen goes black.

Is the GPU a known working card i.e. did you test it in another Mac/PC?
If not I assume the card is failing.

I suppose you installed a HD 5870 Mac Edition?

 

[Iro22]

The graphics driver is not dead because i tested it on ubuntu and the drivers work fine the problem is the high sierra not knowing the graphics driver

 

[KeesMacPro]

Is it a (flashed) Mac Edition card?
A PC version is not compatible , unless you flash the firmware of the card/buy a Mac Version card.

 

[Iro22]

Its a non flashed supported apple graphics driver
But not for high sierra i think pfffff......

 

[KeesMacPro]

Sorry for keeping things clear:
- a driver is part of/something added to the Operating System .
- a ROM / firmware of a video card is part of the card.

The HD5870 PC version is not compatible with a Mac OS.
Whether it's e.g. El Capitan or High sierra doesnt matter.

you can flash the firmware of the card/buy a Mac Version card.

 

[carylee2002]

I find that apple really is making it harder to have gnu compatibility that is outside the norm for their rigs. That is why it is best to put in cards that are known to work from other users . I installed a RX590 card instead of the RX580 and luckily it works. It just doesn't post on your about screen until you get Mojave 10.14.6 installed. It just posts as a generic Polaris video card.

 

[Kurvitasch]

Hello I have an almost identical problem, hoping that there's a solution. Like Iro22 I have an ATI Radeon HD 5870 in my early 2008 3.1.
It is a Mac version. It boots in to the white screen apple logo once, bar loads halfway, and then the screen refreshes but when the loading bar is halfway across again a spinning white circular 'timer' freezes. I have a quad core 2.8 ghz and 24 Mb 6 DDR2 800mz ram with High Sierra. The card works ok with Snow Leopard but on anything else it locks up. According to reports others have this card running, I am not terribly tech savvy and would really appreciate assistance? Many thanks in advance