iMac 2011 K1100M - Target Display Mode Problem

[MrZupp]

Hi, I'm trying to connect a Ryzen PC to my iMac 27" 2011 with a flashed K1100M running High Sierra, ( OpenCore 0.6.4 27" Nvidia config.plist ) but Target Display Mode doesn't work for some reason. I've tried it with a 2018 15" MacBook Pro using a 2m Thunderbolt 2 cable and a Thunderbolt 2 female to Thunderbolt 3 male ( both from Apple ) but there was not even a sign that it's trying to go in Target Display Mode. Also, I've bought a GC-Titan-Ridge and I've had no luck with that either. ( tried connecting pin 3 and 5 but nothing happened, also the software downloaded from Gigabyte won't install, it just unzips a "pack" folder and when I try to run both .exe-s in that folder, nothing happends ) Any help please?

 

[joevt]

Thunderbolt Target Display mode won't work from a PC unless it's using macOS and the Thunderbolt is working for things like Thunderbolt Networking and Thunderbolt Target Disk Mode.

Use your iMac as a display with Target Display Mode - The Apple Repair Station

How to use your iMac as a display with Target Display Mode by Apple Repair Station Specialist in London, UK

applerepairstation.co.uk

 

[MrZupp]

Thunderbolt Target Display mode won't work from a PC unless it's using macOS and the Thunderbolt is working for things like Thunderbolt Networking and Thunderbolt Target Disk Mode.

Use your iMac as a display with Target Display Mode - The Apple Repair Station

How to use your iMac as a display with Target Display Mode by Apple Repair Station Specialist in London, UK

applerepairstation.co.uk

From what i know it accepts any kind of Thunderbolt connection, as I said, it didn't work even with a 2018 15" MBP.

 

[joevt]

From what i know it accepts any kind of Thunderbolt connection, as I said, it didn't work even with a 2018 15" MBP.

A macOS driver "AppleThunderboltEDMSource.kext" is used for transmitting display data from a Thunderbolt Mac to a Thunderbolt iMac that is in Thunderbolt Target Display Mode and has a corresponding input driver "AppleThunderboltEDMSink.kext". Thunderbolt TDM is more like DisplayLink than it is like DisplayPort. Well, maybe someone with a working Thunderbolt TDM connection can prove this with output from AGDCDiagnose.
#7,978

If the iMac in Thunderbolt TDM behaved like a Thunderbolt display, then the AppleThunderboltEDMSource.kext would not need to exist.

The older iMacs with DisplayPort TDM can accept a normal DisplayPort signal so they can work with Mac or PC.

 

[MrZupp]

A macOS driver "AppleThunderboltEDMSource.kext" is used for transmitting display data from a Thunderbolt Mac to a Thunderbolt iMac that is in Thunderbolt Target Display Mode and has a corresponding input driver "AppleThunderboltEDMSink.kext". Thunderbolt TDM is more like DisplayLink than it is like DisplayPort. Well, maybe someone with a working Thunderbolt TDM connection can prove this with output from AGDCDiagnose.
#7,978

If the iMac in Thunderbolt TDM behaved like a Thunderbolt display, then the AppleThunderboltEDMSource.kext would not need to exist.

The older iMacs with DisplayPort TDM can accept a normal DisplayPort signal so they can work with Mac or PC.

Oh, I see, so the only way is from a mac to mac. But why didn't it work on the 2018 MBP?

 

[joevt]

Oh, I see, so the only way is from a mac to mac. But why didn't it work on the 2018 MBP?

Look into how to use the log stream and log show commands. See if you can find something in the log when you press Command-F2 to switch to TDM mode.

Maybe the TDM driver works with the old AMD GPU but not the new Nvidia GPU? Do you have hardware acceleration working or whatever? Gaming benchmarks working ok with the new GPU? I don't know what is required for TDM from the GPU.

 

[MrZupp]

Look into how to use the log stream and log show commands. See if you can find something in the log when you press Command-F2 to switch to TDM mode.

Maybe the TDM driver works with the old AMD GPU but not the new Nvidia GPU? Do you have hardware acceleration working or whatever? Gaming benchmarks working ok with the new GPU? I don't know what is required for TDM from the GPU.

Everything works, except Target Display Mode, heck even Target Disk Mode works when I connect the Thunderbolt 2 cable to my 2011 17" MBP, the Nvidia Quadro K1100M has metal on macos and runs at native speed. Look into the iMac 2011 GPU Upgrade thread and you'll see that the K1100M supposedly has Target Display Mode on the features list.