AMD HD 7870 Black Secondary Monitor Problem (10.13.6)

Rampage IV Extreme | i7 3820 | Radeon HD 7870

Currently my install is 100% working except that so far I have only been able to get one of my 1080p monitors working with a MiniDP to HDMI cable. I currently am getting a second MiniDP to HDMI cable but for now I am stuck with a DVI to HDMI cable.

The monitor that is working is plugged in via the MiniDP to HDMI. The monitor that isn't working is using the DVI cable. However I also tried switching it to HDMI to HDMI which had the same result. Additionally my second MiniDP output also seems to not be working when I swap the port (even on reboot). For all the other ports, the monitor wakes up but it's black. However for whatever reason, both monitors are still recognized by the OS as well as Hackintool.

I know all my cables are good and work because I updated from an install of El Capitan (which I still have on it's original SSD just in case this install fails) as well as a Windows install. Both monitors worked fine on El Capitan for literally years. El Capitan is just too old now and I need to update to keep up with software updates.

Problem reporting files should provide needed info about how I've configured this install.

submitted by /u/Squizit
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