Freezes with RX580

[scottkendall]

I was thinking maybe hardware issue so I picked up a vega64 to try in place of the rx580. same issue. I think I finally have a reproduction pattern though. It seems that doing a screenshare in microsoft teams will trigger it. I am starting to wonder if it is more an iGPU issue and that encoding video triggers it?

YES, and if you turn it off and set your SM to iMac Pro 1,1 their is a good chance it will go away. Others have said the issue with the 580 on iMac Pro 1,1 and needing dummy kext has been resolved with the latest release of Mojave but I am not sure about that; I left it even after the update. In addition normally the removal the IGPU and use of iMac Pro 1,1 will also make iTunes DRM function correctly.

 

[vinnymac]

Yea, it seems hit or miss, and often people cannot reliably reproduce these issues. In my case I cannot reproduce the problem, transcoding HEVC, FCPX, VideoProc, stress tests, etc do not cause any issue. In fact it usually happens when my system is idle and not high load. I am using 10.14.6 with iMac19,1 and I still get the freezes and I am using one of the most recommended cards. I've been searching for a solution for 6 months, meanwhile Ubuntu and Windows on the same machine work just fine.

 

[scottkendall]

Yea, it seems hit or miss, and often people cannot reliably reproduce these issues. In my case I cannot reproduce the problem, transcoding HEVC, FCPX, VideoProc, stress tests, etc do not cause any issue. In fact it usually happens when my system is idle and not high load. I am using 10.14.6 with iMac19,1 and I still get the freezes and I am using one of the most recommended cards. I've been searching for a solution for 6 months, meanwhile Ubuntu and Windows on the same machine work just fine.

Have you tried turning XMP off, IGPU off and setting your SM to iMac Pro?

 

[vinnymac]

@scottkendall yep. I have turned XMP off ran MemTest86 for 4 passes with 0 errors, disabled iGPU, and used SMBIOS iMacPro1,1 and still received the same freeze. If I run the machine for 24 hours straight, it will randomly happen whether or not it is under any sort of load. Under Windows/Ubuntu, this does not happen at all.

I've tried everything I can find recommended across all sorts of forums and websites. I just started posting here to see if anyone had any ideas though.

 

[scottkendall]

@scottkendall yep. I have turned XMP off ran MemTest86 for 4 passes with 0 errors, disabled iGPU, and used SMBIOS iMacPro1,1 and still received the same freeze. If I run the machine for 24 hours straight, it will randomly happen whether or not it is under any sort of load. Under Windows/Ubuntu, this does not happen at all.

I've tried everything I can find recommended across all sorts of forums and websites. I just started posting here to see if anyone had any ideas though.

Yea that is basically sounds like the issues I was having only not on a Z390 I have Z370. But after replacing most of the hardware at least twice and in some cases three times. For me I found it to be XMP that caused the instability for you it might not be actually the same issue even though it it sounds similar.

 

[vinnymac]

@scottkendall I am really confused as I have disabled XMP before in iMac18,3 and iMacPro1,1 to no avail. But based on what you said I decided to try to set XMP to auto and switched to iMac19,1 after the reinstall and I think this may have been it. I have been running the machine for 40 hours now this way with no crash. Sometimes I have seen a crash after a week so I will need to test this more to be 100% certain.

Thanks so much for pointing in this direction. I find it extremely strange that the XMP I profile that runs my RAM at the speed it is rated at would cause this issue. Especially since it is entirely stable in Windows & Ubuntu, and runs MemTest86 for 4 passes with 0 errors. After setting XMP to auto macOS reports the RAM went from the default 3200 MHz to 2133 MHz.

For anyone else who runs into this problem see the RAM I am using below. It is listed as compatible with the Z390-I chipset I am using.

Corsair Vengeance LED 32 GB (2 x 16 GB) DDR4-3200 Memory
CAS Latency: 16
Voltage: 1.35V
Timing: 16-18-18-36
Part #: CMU32GX4M2C3200C16

 

[scottkendall]

Thanks so much for pointing in this direction. I find it extremely strange that the XMP I profile that runs my RAM at the speed it is rated at would cause this issue. Especially since it is entirely stable in Windows & Ubuntu, and runs MemTest86 for 4 passes with 0 errors. After setting XMP to auto macOS reports the RAM went from the default 3200 MHz to 2133 MHz.

I found it extremely strange as well, as did others who tried to help me for 10 or 11 months with no end in sight. Then one days someone suggested turning off XMP so I did and everything was right as rain. I am guessing that XMP causes some kind of Memory Leek with MacOS and that windows/Linux have enough built in error correction to keep the system from crashing. Remember MacOS is designed to run on a Finite set of hardware, any alteration to that hardware can produces undeniable results. Your memory tests past because there is nothing wrong with the memory, but something with XMP, MacOS, and encoding/decoding of multi media cause the perfect storm of instability.

Once you have had the system up for a week or what ever and you are content the system is not crashing any more, you can set the speed of the memory manually without enabling XMP. There is a dropdown list on one of the bios screens I think it is AI tweaker there is a memory frequency setting change it to your memory speed.

I perf to use iMac Pro 1,1 because I find that having the IGPU disabled allows iTunes, Netflix, Hulu DRM content to play.

 

[vinnymac]

@scottkendall I decided to try out iMacPro1,1 with the memory profile on auto, and unlike iMac19,1 my memory is shown as running @ 3200MHz with this configuration. I'll see if this is also stable, as I'd rather have a better performing machine if I can, even if that is at the sacrifice of an authentic build with iGPU + QuickSync.

 

[scottkendall]

@scottkendall I decided to try out iMacPro1,1 with the memory profile on auto, and unlike iMac19,1 my memory is shown as running @ 3200MHz with this configuration. I'll see if this is also stable, as I'd rather have a better performing machine if I can, even if that is at the sacrifice of an authentic build with iGPU + QuickSync.

A real I Macpro does not have IGPU so it is authentic... even better DRM content works in this configuration.

 

[rnkr777]

I suppose that it's CPU issue (i7-7700K in my case). I've changed MB and PSU, two completely different RX580s, but freezes seem to be gone right after switching to another slot on the MB.