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echo44

macrumors 6502
Original poster
Jan 21, 2008
373
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Hi I have a iMac pro 10core 64gb 2 TB
I am having kernel panics and spontaneous shutdowns
It seems this is a common problem
I have tried everything such as erase HD reinstall system software
disable T2, disable file vault
no daisy chain
disable power nap
I am still having crashes! I have read elsewhere this is a common problem.
Some people have gone through 2 replacements?
Wondering if anyone out there has a solution?
 
I do get occasional reboots, when the machine is in sleep mode. No kernel panicks though. Probably another software issue. Only solution I imagine is a software update from Apple. Call Apple support and let them know about your problems. (Are you listening, Tim Cook?)
 
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It’s slightly concerning that we’re over 100 days into the iMac Pro’s release and we haven’t seen any software updates yet to address some of the initial bugs. I hope this isn’t a sign of Apple’s “commitment to pro users”.
 
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I have had a few kernel panics on my iMP, mostly during startup and heavy disk operations. Every time I get a kernel panic it has something to do with the T2 co-processor barfing. I'm sure when we see the next iteration of High Sierra (due any day now) it should fix some of the bugs. I'm actually planning on reinstalling my system tonight because of a disk partitioning error that resulted in 256 GB of space becoming unusable (Requires disk reformat to fix). I suggest reinstalling the OS, as that helped me the first time.
 
It’s slightly concerning that we’re over 100 days into the iMac Pro’s release and we haven’t seen any software updates yet to address some of the initial bugs. I hope this isn’t a sign of Apple’s “commitment to pro users”.
Not true, they've delivered at least 2 Vega driver updates in that time. One of which solved an application crash issue that I was having. Of course the notes for those patches say nothing about driver updates, but when your machine has to reboot twice to install, they're updating drivers and/or firmware.

(Edit: It was at least four Vega driver updates. The first stopped that app crash from taking down the whole system. The second reversed that. The third duplicated the effect of the first, and the 4th fixed the crash problem itself.)

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I do get occasional reboots, when the machine is in sleep mode. No kernel panicks though. Probably another software issue. Only solution I imagine is a software update from Apple. Call Apple support and let them know about your problems. (Are you listening, Tim Cook?)
At least 3 times a week, I have some video or audio problem that requires a reboot to fix. Yesterday it was my main display going black. But I haven't had any spontaneous reboots for months, and those were when the iMP was waking from sleep.

Make sure that you let Apple collect your app analytics, or they won't know about your problems. Calling them won't provide nearly as much information as their crash analysis system.
 
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Yeah I got my iMac Pro to shutdown (it's 1 week old) during heavy video encoding but this has yet to happen again.
It said something about "watchdog" and "BridgeOS". Not sure what to think so far about that, it's still under warranty but as you said, it seems to be a common bug thus even if it's hardware i'd rather wait to send it back to Apple and have them fix it when it common to them than just swapping the machine for the same bug.
 
Yeah I got my iMac Pro to shutdown (it's 1 week old) during heavy video encoding but this has yet to happen again.
It said something about "watchdog" and "BridgeOS". Not sure what to think so far about that, it's still under warranty but as you said, it seems to be a common bug thus even if it's hardware i'd rather wait to send it back to Apple and have them fix it when it common to them than just swapping the machine for the same bug.
If you're seeing kernel panics relating to "WatchDog" or "BridgeOS" that has to do with the T2 coprocessor offloading from the main CPU. It looks like the offloading process between the CPU and T2 coprocessor still has some bugs in it. The next iteration of macOS will likely contain fixes that make this offloading more stable. This is not a hardware issue, it's a firmware issue. Don't trade in your iMac Pro just because you're seeing these crashes at this point - the system architecture is just so new that they haven't worked out all of the kinks yet, and that's to be expected.
 
I am sticking by the assumption that old software and previous system files are more likely the culprit with this bleeding edge machine.
I only installed the latest versions of apps I needed and relied on iCloud and other cloud storage to get what I had elsewhere and mine has been on for at least 35 days with zero issues.

Some of the sleep and audio issues do seem to be coming up over and over again for many though.

The only annoying thing about the iMac Pro so far is having to log in when waking up from sleep.
I guess I never really worried about security.
 
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I am sticking by the assumption that old software and previous system files are more likely the culprit with this bleeding edge machine.
I only installed the latest versions of apps I needed and relied on iCloud and other cloud storage to get what I had elsewhere and mine has been on for at least 35 days with zero issues.

Some of the sleep and audio issues do seem to be coming up over and over again for many though.

The only annoying thing about the iMac Pro so far is having to log in when waking up from sleep.
I guess I never really worried about security.

I didn't migrate. I set up a new computer... So no, not old stuff. I was just using handbrake with 2 sessions at the same time, and I got a watchdog/bridgeOS panic. I did it again though and no problem ever since.

Sound issue is 100% replicable though, just play some video on VLC, and try to use system sounds (empty trash, put a file in the trash) and these sound events will stutter.

Luckily, proper sound that is not system sound is perfectly fine so I don't care, but at this point OS X feels buggier than Windows ever was... And to think Steve was mocking Vista with the "Hello I'm a Mac ads"...
 
I didn't migrate. I set up a new computer... So no, not old stuff. I was just using handbrake with 2 sessions at the same time, and I got a watchdog/bridgeOS panic. I did it again though and no problem ever since.

Sound issue is 100% replicable though, just play some video on VLC, and try to use system sounds (empty trash, put a file in the trash) and these sound events will stutter.

Luckily, proper sound that is not system sound is perfectly fine so I don't care, but at this point OS X feels buggier than Windows ever was... And to think Steve was mocking Vista with the "Hello I'm a Mac ads"...

Bummer they aren’t working as before for sure but I couldn’t judge a computer entirely on how it performs with two free apps.
 
Bummer they aren’t working as before for sure but I couldn’t judge a computer entirely on how it performs with two free apps.
I have been having the same problem everyone else is writing about in Apple Support communities and all over the internet. I have sent 4 files x2 separate times to Apple engineering (4 gigs each time) and they have finally determine it is the embedded Raideon Pro Vega 64 video card which part of the motherboard (not plug in video card). I have new motherboard on order that is going to be replaced. I have also read about folks getting their iMac Pro replaced and the same problem happening with clean "Macs" with no additional software or peripherals (I am assuming Apple did not know with these folks that the GPU was the issue). My take is that Apple has found the problem and they probably had to get AMD to fix the GPU in their video card, so now the new motherboard and hopefully new AMD Raideon Pro Vega 64 card are fixed. I will let you know. If you are not sending large files to Apple to review (what I did) you may be wasting a lot time with all these theories out there. My reason for posting is, if everyone does what I did (send crash files to Apple), we may all get to the bottom of this quicker. I not certain this is the fix until I get the new motherboard with new embedded video card and the problem (kernel crashes) goes away. My kernel crashes happen now nonstop. that is another question, why did the frequency increase so much if it was always a hardware issue.
 
My kernel crashes happen now nonstop. that is another question, why did the frequency increase so much if it was always a hardware issue.
Because the software is what the GPU runs. If the GPU wasn't being run at 100% before a driver update sped it up, or some part of it (the shading units, for example) are given more difficult code to run, then circuit faults or thermal issues are more likely to appear.

Or put another way: My iMac Pro runs World of Tanks and Master of Orion pretty well, even with other apps running in the background. But Fortnite stutters (obvious thermal throttling) and then brings down the entire OS (kernel panic) every time. While my Photogrammetry app will crash out just the app when the GPU isn't disabled while using just one of its many GPU-accelerated functions.
 
Because the software is what the GPU runs. If the GPU wasn't being run at 100% before a driver update sped it up, or some part of it (the shading units, for example) are given more difficult code to run, then circuit faults or thermal issues are more likely to appear.

Or put another way: My iMac Pro runs World of Tanks and Master of Orion pretty well, even with other apps running in the background. But Fortnite stutters (obvious thermal throttling) and then brings down the entire OS (kernel panic) every time. While my Photogrammetry app will crash out just the app when the GPU isn't disabled while using just one of its many GPU-accelerated functions.
Not sure why you are posting the miscellaneous stuff. The thread started out as iMac Pro kernel crash that MANY people experiencing. It seems we are trying to share common experiences and see if anyone else is having this problem. I have the engineers at Apple telling me they think it is my Radeon Pro Vega 64 card. We are trying to find commonality.
 
Not sure why you are posting the miscellaneous stuff. The thread started out as iMac Pro kernel crash that MANY people experiencing. It seems we are trying to share common experiences and see if anyone else is having this problem. I have the engineers at Apple telling me they think it is my Radeon Pro Vega 64 card. We are trying to find commonality.
What I was trying to point out is that this is not JUST a hardware issue. Poorly designed software (especially at the OS level) can easily overheat and damage hardware that's running hot already. Software can also be used (as with the Meltdown/Spectre CPU vulnerabilities) to work around known hardware issues (with downsides of course).

Since buying my iMac Pro, one of my apps has gone from taking down the whole system when computing on the GPU (new), to just crashing the app itself (3rd OS update), to taking down the whole system again (4th OS update), to just crashing the app itself again (5th OS update). The hardware didn't change, or the app. It was software changes at the OS level that caused the differences.
 
What I was trying to point out is that this is not JUST a hardware issue. Poorly designed software (especially at the OS level) can easily overheat and damage hardware that's running hot already. Software can also be used (as with the Meltdown/Spectre CPU vulnerabilities) to work around known hardware issues (with downsides of course).

Since buying my iMac Pro, one of my apps has gone from taking down the whole system when computing on the GPU (new), to just crashing the app itself (3rd OS update), to taking down the whole system again (4th OS update), to just crashing the app itself again (5th OS update). The hardware didn't change, or the app. It was software changes at the OS level that caused the differences.

Yes. And with 10.13.5 I have some app that's causing KPs regularly now. I have no idea what it is; it's not even logging properly. :(
 
Since buying my iMac Pro, one of my apps has gone from taking down the whole system when computing on the GPU (new), to just crashing the app itself (3rd OS update), to taking down the whole system again (4th OS update), to just crashing the app itself again (5th OS update). The hardware didn't change, or the app. It was software changes at the OS level that caused the differences.

Unless is a bad or weak spot on the SSD, or perhaps ram or a buffer, that as you update software gets used or not used by your app or another process or swap which will either crash the mac entirely or just the app .... depending on whats using it. I've seen this and stranger things happen, dunno if its applicable to the iMac pro architecture, however. Just saying that there are hardware or design problem symptoms that change based on how the OS or app is using the machine.
 
Unless is a bad or weak spot on the SSD, or perhaps ram or a buffer, that as you update software gets used or not used by your app or another process or swap which will either crash the mac entirely or just the app .... depending on whats using it. I've seen this and stranger things happen, dunno if its applicable to the iMac pro architecture, however. Just saying that there are hardware or design problem symptoms that change based on how the OS or app is using the machine.
I'm running a fresh install of 10.13.4 right now, and the compute bug I was talking about still persists. As does my Sonnet eGPU+Rx580 (sold by Apple last summer), which if plugged in will take down the system during sleep every single time.

It's obviously not a hardware failure on the Sonnet box or the card, it's a software problem that got introduced when Apple took their eGPU support out of beta (ha!) with 10.13.4.

Similarly, if the system is somehow allowed to do something CPU-intensive with the fans off during sleep, then you're going to see the overheating problems others have talked about. It doesn't matter if a legacy driver is at fault. The OS should be throttling the CPU to whatever the maximum safe fan-off speed is in that mode.
 
Ever since I installed 10.13.5, I have been seeing "spinlock" kernel panics. I installed the combo update too... same issue. Anyone have any idea what could be causing this? The machine had a fresh install (non migrated) from 10.13.2 on... no issues at all until 10.13.5

EDIT:

I turned off all the nap / spindown features, and also shut off secure boot - and reinstalled the OS from recovery.

So far so good... no KPs in 12 hours. We'll see!
 
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Ever since I installed 10.13.5, I have been seeing "spinlock" kernel panics. I installed the combo update too... same issue. Anyone have any idea what could be causing this? The machine had a fresh install (non migrated) from 10.13.2 on... no issues at all until 10.13.5

EDIT:

I turned off all the nap / spindown features, and also shut off secure boot - and reinstalled the OS from recovery.

So far so good... no KPs in 12 hours. We'll see!

My 10-core iMac Pro has been a dud from day one (from early May). I get kernel panics and spontaneous reboots regularly, and they come in waves. I just recently had it run for over 3 days with no problems, then yesterday it froze and rebooted while I was using it, and then has rebooted itself 8 times in the next 12 hours, sometimes only minutes after the previous time.

It seems like heavy use of the Photos app is a good way to cause a kernel panic (though not all the time, and it crashes when not running Photos too). It also is much more crash-happy when I have both of my external monitors connected.

My previous 5K iMac had no problem running the same two external monitors. I've tried several different USB-C to DisplayPort and USB-C to HDMI adapters, too.

This computer has been an incredibly frustrating experience, and for the price paid I'm extremely unhappy with it.
 
Ever since I installed 10.13.5, I have been seeing "spinlock" kernel panics. I installed the combo update too... same issue. Anyone have any idea what could be causing this? The machine had a fresh install (non migrated) from 10.13.2 on... no issues at all until 10.13.5

EDIT:

I turned off all the nap / spindown features, and also shut off secure boot - and reinstalled the OS from recovery.

So far so good... no KPs in 12 hours. We'll see!
I was also running an un-migrated fresh install until 10.13.4 – Then I started seeing massive rebooting problems. Did a fresh install of 10.13.4, & left off the RAID drivers that were throwing false errors. Now I'm back to my usual 1-2 reboots a week. Only problem is that plugging in my eGPU will cause the system to crash during sleep again.
 
I was also running an un-migrated fresh install until 10.13.4 – Then I started seeing massive rebooting problems. Did a fresh install of 10.13.4, & left off the RAID drivers that were throwing false errors. Now I'm back to my usual 1-2 reboots a week. Only problem is that plugging in my eGPU will cause the system to crash during sleep again.

Like concluded said above, I still do get random KPs now and then, especially connected to Photos running and/or using the external display heavily. We will see...

Note/edit: This past weekend I used the iMP heavily for an edit for 2 days, with zero crashes. Of note - I did NOT have a 2nd screen attached. With it attached, I had seen KPs now and then. I did use it for hours with the screen attached last week after the latest HS update with no issues.. maybe that contained a hidden fix?

EDIT 2: I can say that 10.13.6 definitely did something. I have not seen a KP since.
 
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