Multiple Monitors Don't Work

[laxamar]

Hi, I'm having a weird problem for multi-monitors:
If I choose in SMBIOS a lower model - iMac14,2 - I get all monitors working both on DP and HDMI on startup. Things go horribly wrong on sleep.
If I switch to something newer corresponding to my Gear - iMac18,3, then the system seems to boot correctly, but only HDMI ends up working. The displayport monitor never gets activated, even though its the one that displays the Apple logo during boot. This is literally with the same setup, only difference is in SMBIOS

Now for things that might be relevant : It used to work with the previous MacOS 10.13.3
10.13.4 did something that killed it. I accidentally discovered that iMac14,2 will make it boot at least. I wanted to move to 10.13.5 but don't know what else might get killed.

Have done the obvious things like upgrade latest lilu, whatevergreen and Shiki

Want to move back to iMac18,3 so that next versions of MacOSX will think not obsolete my setup.

Any help would be appreciated.

 

[Stork]

laxamar, since were not telepathic, we need to know your graphics card make/model #. Or are you using on-board graphics? In either case, please update you Profile's Component list. TIA.

 

[laxamar]

laxamar, since were not telepathic, we need to know your graphics card make/model #. Or are you using on-board graphics? In either case, please update you Profile's Component list. TIA.

Ooopsie. Forgot that *little* detail. I'm a professional ... I swear!

Sorry, the graphics card is an MSI RX480. My motherboard (ASUS H110M-E/M.2) does have a built-in Intel Graphics which I've enabled/disabled to no avail. However, currently disabled and it seems to have fixed the sleep issues I was having, unless the latest Whatevergreen did that.

On a related note, I can't find any *explanation* of what these boot parameters do:
-rad4200 igfxgl=1 shikigva=4
I've been keeping them for ever. Would love to know what they do and what values shikigva take and what they mean. Blindly copying settings doesn't help ....

 

[zakklol]

Ooopsie. Forgot that *little* detail. I'm a professional ... I swear!

Sorry, the graphics card is an MSI RX480. My motherboard (ASUS H110M-E/M.2) does have a built-in Intel Graphics which I've enabled/disabled to no avail. However, currently disabled and it seems to have fixed the sleep issues I was having, unless the latest Whatevergreen did that.

On a related note, I can't find any *explanation* of what these boot parameters do:
-rad4200 igfxgl=1 shikigva=4
I've been keeping them for ever. Would love to know what they do and what values shikigva take and what they mean. Blindly copying settings doesn't help ....

shikivga arguments are documented here: https://github.com/vit9696/Shiki/blob/master/Shiki/kern_start.cpp#L18

 

[AlGrey]

Hi, I'm having a weird problem for multi-monitors:
If I choose in SMBIOS a lower model - iMac14,2 - I get all monitors working both on DP and HDMI on startup. Things go horribly wrong on sleep.
If I switch to something newer corresponding to my Gear - iMac18,3, then the system seems to boot correctly, but only HDMI ends up working. The displayport monitor never gets activated, even though its the one that displays the Apple logo during boot. This is literally with the same setup, only difference is in SMBIOS

Now for things that might be relevant : It used to work with the previous MacOS 10.13.3
10.13.4 did something that killed it. I accidentally discovered that iMac14,2 will make it boot at least. I wanted to move to 10.13.5 but don't know what else might get killed.

Have done the obvious things like upgrade latest lilu, whatevergreen and Shiki

Want to move back to iMac18,3 so that next versions of MacOSX will think not obsolete my setup.

Any help would be appreciated.

I have the same issue with anything above 10.13.3. Did someone found why it's acting like this with iMac18,x ?

 

[BreBo]

@AlGrey, please update your profile (personal details) with your Motherboard, CPU and iGPU or Graphics Card(s).
If you have a prebuilt computer enter make and model instead of motherboard.

Profiles are mandatory so that others can assist you.