Kernel panic crashes since updating my OS on iMac 27"

[TacoGas]

ok I have a iMac 27" 2020 mac, 3.8 Ghz 8 -core intel core, AMD Radeon Pro 5500 XT 8 GB, 128 GB 2667 MHz DDR4, now running MacOS 15.3.2
I have had big problems crashing after upgrading from the original OS which was Catalina. When I first got the machine in 2020 I upgrade the OS and it was a nightmare. After a month apple finally was able to get me back to the beginning with Catalina. Everything went back to normally and I worked with the machine professionally with 128 gb of ram. I finally upgraded the OS in 2025 when I was done with all my projects. It was a disaster. I have nothing but kernal panics even when the machine is at rest. Never seen any thing or heard anything like it. I have gone through all that everyone has spoken of hear. I only need this machine for a few more years. I have read the posts regarding these machines running into this issue when running a second monitor. The only solution I have come across is people adding a Dell d-6000 dock to connect the second monitor with nothing else attached to the dock. I was wondering if a Iogear GUD3C4K2TAA Dock pro universal dul view docking station. It seems to actually support Mac os were the D-6000 doesn't technically support mac OS. These two options have become my last home for this machine. I hate to say it but I knew I would run into problems with upgrade but I finally had to to be able to run some new publishing software. I was hoping I would be able to fix what ever problems came. I have been on this for months

 

[Bigwaff]

Catalina > Sequoia upgrade? Verified all your software is compatible with Sequoia?

128GB RAM and OS upgrade? Was the RAM upgraded to 128GB? If so, put back the original RAM modules and see if macOS is still unstable.

Share kernel panic log.

Hard to really offer more suggestions w/out a clear understanding of your set up and workflows. Ex. How much space is left on internal storage? What all peripherals are attached to iMac? What specific software installed? iMac connected to network wirelessly or wired? More details the better.

 

[Brian33]

Just to clarify, do the kernel panics stop happening if you don't use an external monitor?

How many external monitors are you using?

The only solution I have come across is people adding a Dell d-6000 dock to connect the second monitor with nothing else attached to the dock. I was wondering if a Iogear GUD3C4K2TAA Dock pro universal dul view docking station. It seems to actually support Mac os were the D-6000 doesn't technically support mac OS.

Dell dock:
https://dl.dell.com/manuals/all-products/esuprt_electronics/esuprt_docking_stations/dell-universal-dock-d6000_user's%20guide_en-us.pdf
"DisplayLink Manager Menu" under Features.

Iogear dock:
https://iogear.com/pages/gud3c4k2taa
"DisplayLink chip allows for Windows and macOS compatibility"

I'm no expert on docks or monitors, but these two USB-C docks seem pretty basic to me. They both mention DisplayLink capability (which I don't know anything about) -- is this what you think might prevent your kernel panics?
If your main question is about whether the two docks are equivalent, or about DisplayLink itself, you might get better responses by changing the thread title to include those words.

Hope you can get it sorted out.

 

[TacoGas]

Catalina > Sequoia upgrade? Verified all your software is compatible with Sequoia?

128GB RAM and OS upgrade? Was the RAM upgraded to 128GB? If so, put back the original RAM modules and see if macOS is still unstable.

Share kernel panic log.

Hard to really offer more suggestions w/out a clear understanding of your set up and workflows. Ex. How much space is left on internal storage? What all peripherals are attached to iMac? What specific software installed? iMac connected to network wirelessly or wired? More details the better.

128GB of ram was installed when I purchased back in 2020. Once I went back to Catalina it was fine for the next 4.5 years. Mainly running photoshop for animation based projects. All good until I upgraded a few months ago. Threads here seem to point to the 2020 iMacs having issues with running dual monitors. The fix was to run a Dell D6000. Sounds like displaylink was key. It crashes just sitting there. Hearing the same from many others. 5500 xt gpu seems to be a common area that has been pointed to.

 

[TacoGas]

Just to clarify, do the kernel panics stop happening if you don't use an external monitor?

How many external monitors are you using?


Dell dock:
https://dl.dell.com/manuals/all-products/esuprt_electronics/esuprt_docking_stations/dell-universal-dock-d6000_user's%20guide_en-us.pdf
"DisplayLink Manager Menu" under Features.

Iogear dock:
https://iogear.com/pages/gud3c4k2taa
"DisplayLink chip allows for Windows and macOS compatibility"

I'm no expert on docks or monitors, but these two USB-C docks seem pretty basic to me. They both mention DisplayLink capability (which I don't know anything about) -- is this what you think might prevent your kernel panics?
If your main question is about whether the two docks are equivalent, or about DisplayLink itself, you might get better responses by changing the thread title to include those words.

Hope you can get it sorted out.

No crashes without using second monitor. A co worker has the same machine and runs a cintiq with no problem. I was told that display link support in the docks running dedicated with the monitor being the only device connected is the only thing found to get around the "kernel panic" issue. There's a few threads in the forums here talking about this for years. Incredible to read. It ran fine with Catalins installed for almost 5 years until the upgrade. I worked at netflixs during the 5 years and we were told not to update the OS by any means. It was known to be an issue. Sure enough when I purchased my own machine it crashed so bad after upgrading from catalina I had apple reinstall it. So it stayed that way for years. It crashed with nothing installed but the dual monitor, a wacom tablet, and photoshop. Its not wacom or PS. That I ruled out long ago

 

[TacoGas]

Here's an link to people talking about this. https://forums.macrumors.com/thread...c-crashes-whenever-using-2nd-monitor.2310301/

 

[TacoGas]

I also ran several different monitors over the past 5 years with no issues at all. Some every high end and some more economic. Going back to catalina is obviously not going to happen. So this dock option is the only thing I can find that has worked in anyway

 

[Bigwaff]

Thunderbolt 3 dock might be option. TB3 docks can drive two external displays. I know a CalDigit TS3 Plus TB3 dock can be had on eBay for under $100.

 

[TacoGas]

Thunderbolt 3 dock might be option. TB3 docks can drive two external displays. I know a CalDigit TS3 Plus TB3 dock can be had on eBay for under $100.

So I set up the Iogear dock and Im running USB-c to dock and Displayport of to the second monitor. Nothing else is connected to the dock. I'll push it and see if it works. That "CalDigit TS3 Plus TB3 dock" dock is pretty interesting.

 

[TacoGas]

Could the CalDigit TS3 Plus TB3 dock have usb-c to the monitor set up? I had that recommended on the iMac with a direct link to the monitor instead of using display port. That didn't solve the issue but was a recommendation originally as a better set up in general. Most of the docks I see have HDMI or displayport ports. I see an additional usb-c but I don't know if that can be used for a second monitor. My monitors have the usb-c option

 

[PaulD-UK]

The only USB-C port on a TB3 dock that carries the video signal is the downstream (second) TB3 port.
That is designed to provide a connection point for a USB-C (or TB3) monitor.

 

[Mactech20]

Process of elimination.

Don't use any external devices, does it still crash?

Try only using 1 RAM chip at a time, does it still crash?

If its still crashing go back to Catalina, does it still crash? If no, it's a software issue most likely, good news! If it crashes on Catalina now and you have tested the ram it's most likely hardware. On that model that's a death sentence.

 

[TacoGas]

Process of elimination.

Don't use any external devices, does it still crash?

Try only using 1 RAM chip at a time, does it still crash?

If its still crashing go back to Catalina, does it still crash? If no, it's a software issue most likely, good news! If it crashes on Catalina now and you have tested the ram it's most likely hardware. On that model that's a death sentence.

The rams fine. It crashes with everything disconnected except the monitor. If the second monitor is connected all the problems appear. Its not the monitor itself. The thread I included above shows all the people that have delt with this same issue. Going back to Catalina would be a nightmare and doesn't solve the main problem. I had to finally update the OS so I could run modern publishing software. If I can't get the current OS's to work then the machine is done. And most likely have to go with a PC due to my high ram needs. The price of having to have Apple install 128GB of memory is three times higher. I need a good work machine but I'm not going to spend $6,000 to $10,000. Or drop down to a mac mini and end up with have the ram for the same price. I got almost 5 years of solid use out of that machine. I knew the OS upgrade would most likely end the use of that machine as a work station. I have probably spent 6 months zeroing in on what is going on with these machines going back to 2020. I know if I hook up a cintiq and eliminate the monitor the machine will work. That's $1500 to $2000. But I need two monitors for my work not a cintiq.

 

[TacoGas]

The rams fine. It crashes with everything disconnected except the monitor. If the second monitor is connected all the problems appear. Its not the monitor itself. The thread I included above shows all the people that have delt with this same issue. Going back to Catalina would be a nightmare and doesn't solve the main problem. I had to finally update the OS so I could run modern publishing software. If I can't get the current OS's to work then the machine is done. And most likely have to go with a PC due to my high ram needs. The price of having to have Apple install 128GB of memory is three times higher. I need a good work machine but I'm not going to spend $6,000 to $10,000. Or drop down to a mac mini and end up with have the ram for the same price. I got almost 5 years of solid use out of that machine. I knew the OS upgrade would most likely end the use of that machine as a work station. I have probably spent 6 months zeroing in on what is going on with these machines going back to 2020. I know if I hook up a cintiq and eliminate the monitor the machine will work. That's $1500 to $2000. But I need two monitors for my work not a cintiq.

I should add when I had Apple originally reinstall Catalina it took them almost a month to get it done. It wasn't pretty. Can't imagine trying to do that now without the new warranty. But I already know what it will do in Catalina. I had to finally move away from it for other needs. I use to hope for 7 years out of a mac work station before issues. Didn't make it to 5 this time.

 

[PaulD-UK]

@TacoGas In that long thread about the problem you linked to, the LG 5K Ultrafine (Thunderbolt) monitor was reported as working 'fine', and no one seems to have tried an Apple Studio Display.

If you wanted to continue with the iMac it might be worthwhile trying it with an ASD, as that can work in TB3 mode...

 

[TacoGas]

The apple studio display might be worth trying. If I have to give up on this machine and I stick with a mac mini or laptop I would probably I have ordered a ASD to try and get close to the iMac screen. I though they were the same display as the iMac but I guess its different. I got use to using the iMac screen. Not color accurate as my professional monitors but good enough. So I could put the monitor to use if I stayed with mac hardware.

Unfortunately the IOGear did not solve the problem. So thats out. The LG 5K ultrafine (thunderbolt monitor) I'll have to go back an investigate the thread on that. Before switching to the IOgear dock I was running USB-C From iMac to monitor directly. No adapters just usb-c to usb-c cable. Through the thunder bolt ports on the iMac. Its back to that now. If I could get my hands on a ASD that would be cool to try.