Radeon Compatibility Guide - ATI/AMD Graphics Cards

[Fl0r!an]

Seems to be a Cape Verde chip, so spoofing the device ID to 0x683D1002 should do the trick (have a look at section 4 of the 1st post for details).

In case you're booting to black screen: Install Verde.kext.

 

[diedo]

Anyone please can provide us with the right framebuffers from Sierra.in correct format

 

[nightlite]

I just discovered that amd cards have problems waking up from sleep even on Windows and requires me to disable "PCI link power management" to Off in Power Settings. I wonder if this provides any insight into El Capitan's wake issues with AMD video cards?

 

[Fl0r!an]

Interesting. Might be possible to do something similar through DSDT edits in OS X, but I honestly don't know.

 

[L0g4nAd4ms]

@nightlite what do you mean ? what exactly did you witness on windows ?

 

[dokter.bibber]

All DP 1.2 ports on the R9 280X are 4K capable!

Just note that you'll lose sleep/wake (as with all other AMD cards), unless you use the iGPU=Primary workaround. Besides that it should work fine!

I want to get a R9 280X (with 2 x mini-DP + HDMI + DVI-I) for a Hackintosh build, but I don't want to make an expensive mistake.
So about losing sleep/wake with AMD Radeon R9 280/280X. To prevent a blank (black) screen, is it possible to prevent sleep state by setting the minimum clock slightly higher than default ?
So that the video card never enters sleep state and doesn't use much more power.
If this works, it could also allow for hot swap of monitors connected to DP maybe ?
Because the DP ports wouldn't disconnect.

 

[Fl0r!an]

You can't sleep the whole system except the graphics card, that won't work. The only known workaround to the black screen bug is booting with iGPU=Primary.

 

[dokter.bibber]

I meant the minimum clock of the R9 280X. So that the video card looks busy to the OS, or whatever takes care for putting the card to sleep.

 

[Fl0r!an]

I'm talking about system sleep. The whole system will be powerless (besides minimal power needed to maintain the RAM content), you can't keep the GPU "alive" in that state.

If you're fine without system sleep then there's nothing to worry about, you can easily disable it in OS X.

 

[dokter.bibber]

That's exactly what I want. I do not want the system to go to sleep. I didn't realise that you could turn off system sleep in OS X.
(You know, Macs and power saving every last drop) I want to put the system to sleep manually, or shut it down.

Thanks.