I have two Hacks:
One: X58, Xeon X5670, legacy boot (Clover R4945), AMD RX Vega 64 8GB GPU (Gigabyte OC model). No iGPU. MacPro 5.1 SMBIOS.
Two: H77, i5-3550, UEFI boot (Clover R4945), AMD 7970Ghz / R9 280X 3GB GPU. No active iGPU (it's Intel 2500, not supported). iMac 14.2 SMBIOS.
Both are running macOS 10.14.6.
On both these systems I have problems with AMD graphics:
- On both systems: from boot, I get black screen on most or all GPU ports. Console log is full of errors, in particular "CRITICAL ERROR : VBLANK interrupt has not been generated in time!", and Activity Monitor shows 100% CPU on kernel. To resolve these issues, I must sleep & wake. After first sleep, I get a picture on all monitors.
- On RX Vega 64 on X58, this problem is even worse: I get black screen on all monitors, and trying to sleep the system will cause it to hang. The only way I can sleep is by booting with no monitors connected to any GPU port. With this done, there are no Console errors, and I can put the system to sleep, then wake it, then I will have a picture on all monitors.
- On both systems: I have no HW h264/h265 encode/decode. This is shown by apps such as Video Converter Pro and MacX Video Converter Pro. Also, playing a 4K video in eg VLC will show very high CPU usage (300-500%)
- On X58 with RX Vega 64 only: my 4K monitor sometimes won't connect at 4K@60hz. I am using Displayport 1.2 cable, and in Windows 10 it's fine, and also was fine on my older R9 280X GPU. But with Vega 64 in macOS, sometimes it connects at 4K@60, sometimes it's 4K@30, and sometimes it's 2840x1080 @ 60. I don't yet know what causes it to sometimes work, sometimes not. Today it took me literally 2 hours of rebooting to get it to come up in 4K@60hz.
On H77 system I am also using WEG 1.3.2, but i don't know if this is changing anything; I get same issues with and without WEG.
I have tested with every possible combination of graphical settings I know about - WEG on/off; InjectATI on/off; every possible WEG option; Clover Framebuffer patching; and more. Nothing I have ever tried can resolve any of these issues.
I am sorry for posting so many issues here, but I have spent literally many days trying to solve these problems, and have got nowhere. I have posted many times on InsanelyMac forum, but no-one seems able to help.
Right now I have a workaround for problem #1, ie I can sleep & wake to get all monitors working. It is quite annoying and slow on the X58/Vega 64 system, because I must boot without any monitors connected, but it does work. And problem #3 (4K@60) only happens sometimes, and once I have it fixed I can simply not turn off the PC to avoid it happening again.
So the one problem I have no workaround/solution for is #2 - missing HW encode/decode. I know other AMD users have working HW encode/decode, but I don't know why it doesn't work for me.
If anyone has any ideas for any of these issues, I would be so grateful. I have spent so much time testing/debugging/researching, with no luck.
Thanks in advance.