Radeon RX560/580 outputs (which work/don't work/might work?)

[Regtom]

Trying to find clarification on how the outputs on an AMD natively supported card work/don't work. I picked up an RX560 by suggestion and currently have it working, but with only one monitor. I don't have a displayport, so I'm attempting dual output via the DVI and HDMI ports and can only get output via DVI. I've tested several cables and monitors off the HDMI port to no avail, not even a single monitor.

While researching, I've ran across threads pointing out a need to change the ID of the Hack (which model it is emulating) but also statements that some outputs just don't work. Is there any consistency to this? Will the DVI always work, but not the HDMI? Will this require a combo of DVI and displayport? (I've ordered a displayport to DVI adapter to test)

I've had dual DVI output on my old GTX650 working OOB for years, but neither the GTX1050 I tested or this RX560 are offering dual output. Trying to figure this out. Thanks

 

[dfritchie]

Don't know about the 560, but the 580 I'm using has dual monitors attached and working. One DVI the other is HDMI. I have Lilu and Whatevergreen installed.

 

[Regtom]

Okay, so I have now learned we're not allowed to link to articles on alternative Hack sites so my previous response has disappeared. Here is part of it:

Thanks for pointing this out, I should have included that I used instructions for installing Lilu and Whatevergreen as well, but HDMI output. I did find comments that switching the SMBIOS listing to a MacPro version could work, but that there could then be issues with the change causing a refusal for iCloud/AppleID/ETC. Another article pointed out that changing to a MacPro SMBIOS designation can cause a boot error.

All of this while attempting to upgrade to High Sierra, so it's being a wild ride. I think I'm going to go ahead and make the upgrade and then cycle back to this if the problem isn't resolved (not that I think it will be resolved, but who knows?)