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Dell Precision M6800: HDMI dummy = K4100M on internal display ?


draskostar
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Today I finally got this HDMI dummy from China.

Tishric_display_simulator.jpg

 

Put it in and set mirror displays in settings and voilà! k4100m is showing on internal screen.

 

Right now I am not sure If this is some fake hope or this is actually 3d acceleration coming from k4100m also to my internal screen?

 

Screenshot 2021-05-20 at 20.23.13.png

 

Screenshot 2021-05-20 at 20.30.16.png

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Check your IOReg; built-in LCD registers as an AppleBacklightDisplay...

 

This kind of generic devices are not so much HDMI dummies but display simulators/virtual displays. I don't think it makes your nVidia K4100M prime GPU for the built-in LCD. To me, it's just a temporary cosmetic thingie whilst the virtual display device is connected. You just need to look at what SysInfo->GraphicsDisplays actually shows under the HD4600 iGPU: ain't that the built-in LCD??? What's listed under the nVidia dGPU ?

 

As for display mirroring, remember that it mirrors the built-in LCD on external screens, not the other way round.

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Look under [email protected] (HD4600 iGPU) and under [email protected] (nVidia dGPU).

Again, a built-in LCD registers as AppleBacklightDisplay.

External monitors register as AppleDisplay.

 

For iGPUs, connected screens are listed under the various connectors (=output ports) con0/con1/con2/con3 (the various [email protected]).

For nVidia dGPUs, connected screens are listed under the various connectors (=output ports) A/B/C/D (the various NVDA,Display-A/B/C/[email protected]).

 

Good thing that the dongle was dead cheap, eh?

 

NB: I noticed you use SMBIOS MBP11,5 rather than MBP11,3. Strange choice given that former is fitted with an AMD dGPU when latter is fitted with an nVidia Kepler dGPU. I'd have opted for the latter.

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Afaik, if you want to run only with the nVidia dGPU, you need to disable Optimus. At least that how things worked on the old E6x20/E6x30. With Optimus disabled, the Intel iGPU was off/unused. But then, most of you guys just get a blank built-in LCD which suggests it is not wired to the dGPU.

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@Hervé

If I understand well then this guy did it (user by name @areos gave a solution). Please take I look here on this link:

https://www.insanelymac.com/forum/topic/293967-solved-asus-rog-laptops-with-kepler-cards-not-detecting-dp-2-connected-lcd-display/page/6/

 

Firstly sorry for my noob questions but do you think I can use this EFI string? Where exacltly I should put this in?

 

Thank you very much!

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