Hi guys, hoping for some insight, I have el cap running smoothly on one disk and decided to install sierra to the other disk to see how things went. My issue is that using the internal 530, I can't get dual monitors to work in Sierra.
Setup is 530 GPU, HDMI + DVI
El cap works with the 530 patches (inject intel, ig-platform-id, 4 port patch, two patches to change the connector type). I boot with the DVI monitor turned off, and when I get to the desktop, I turn on the DVI monitor and enjoy dual monitors from there on out. I am using the MacPro 6,1 SMBIOS so I also have to apply the AGDPFix.app fix.
I installed Sierra and it boots fine on either the DVI monitor or the HDMI monitor (I'll describe dual monitor in a sec). Same fixes/patches as for el cap plus I added the Skylake Sierra 530 fixes that remove the glitch in the upper left corner. IOReg reports same ports/port numbers/connector types. I also have the rename GFX0 to IGPU patch.
Now the behavior: if I boot with either single monitor, it works fine. If I then turn on the second monitor, BOTH monitors go dark, and never turn back on, in fact, the system appears to freeze because if I select "restart" then turn on the second monitor, the system never restarts (restart starts a 60 second timer that apparently never counts down).
If I have both monitors turned on at boot, about halfway through the boot cycle, the DVI monitor turns off, and a minute or so after reaching the desktop on the other monitor, the system hangs. "about this mac" always reports the right info and vram.
Is this a smbios thing? change to iMac 13,2? Thanks for your help.