- Joined
- Feb 21, 2017
- Messages
- 194
- Motherboard
- HP Envy 17-U275CL
- CPU
- i7-8550U
- Graphics
- GTX MX150 / HD 620, 1920x1080
- Mac
- Mobile Phone
I'm pretty sure its to do with how the firmware initialises the displays before the Nvidia drivers take over. EFI/GOP seems buggy in firmware settings and it is only turned on as part of 'Windows 8 features'. I'd speculate it only gets tested with Windows, and not by the people who write the module. Heard some people have success with similar sounding problems by using CSM/BIOS graphics code. Another thing i'll add is if i boot with both displays attached they power off when they should be initialised, while the dark screens i was getting post-web driver 10.13 the displays remained on.Vulgo - you also mention you have blank screens if you boot with dual monitors connected - is this still the case ? Have you tried the above ?
The OS seems to keep track of every display you ever used in every port, and if e.g. the device name/path changes in the IO registry new/additional preferences are created/stored.I also looked at my ~/Library/Preferences/ByHost/com.apple.windowserver.UUID.plist & confusingly I see the 2 monitors that are connected however there is 5 entries (3 for the first monitor and 2 for the second). If I look in IOReg I can see 5 entries for the 5 ports on my graphics card, however only 2 of them have a display connected - and these map to the same as the plist. Attached is the plist.
That's it ! The guide I had originally followed for Sierra and High Sierra build said must disable CSM in BIOS. I just set CSM to enabled and it now can boot into Sierra & High Sierra with both monitors connected !I'm pretty sure its to do with how the firmware initialises the displays before the Nvidia drivers take over. EFI/GOP seems buggy in firmware settings and it is only turned on as part of 'Windows 8 features'. I'd speculate it only gets tested with Windows, and not by the people who write the module. Heard some people have success with similar sounding problems by using CSM/BIOS graphics code. Another thing i'll add is if i boot with both displays attached they power off when they should be initialised, while the dark screens i was getting post-web driver 10.13 the displays remained on.The OS seems to keep track of every display you ever used in every port, and if e.g. the device name/path changes in the IO registry new/additional preferences are created/stored.
That's it ! The guide I had followed for Sierra and High Sierra build said must disable CSM in BIOS. I just enabled it and now can boot into Sierra & High Sierra with both monitors connected !
Thanks !
For my problem - I would boot to black screen signal like you if I had 2 monitors connected, but this only occured when CSM was disabled in BIOS.Seems like disabling CSM doesn't do the trick for me... But let's start at the beginning:
For my problem - I would boot to black screen signal like you if I had 2 monitors connected, but this only occured when CSM was disabled in BIOS.
To fix my issue I had to select CSM Enabled in BIOS (Didn't try CSM = Auto but will try it later)
Sorry – I meant enabling CSM corrected it in my post...
So – like on your machine – with CSM disabled I get black screen with more than one screen connected while booting.
If I however enable it, I can't even get past that line while booting...
In my BIOS I have the following settings under CSM when I set it to enabledSo – like on your machine – with CSM disabled I get black screen with more than one screen connected while booting.
If I however enable it, I can't even get past that line while booting...