GA-Z77N-Wifi opencore Boot Gui Problem

[mchammer26]

Hello,

switched my GA-Z77N-Wifi i7-3770S (F3 BIOS) from Clover 5119 to opencore 0.6.3 (Catalina 10.15.7). Everything is just working fine. The system is connected via HDMI to an ACER Predator XB271HU 27"-Display using the builtin HD4000 graphics. But still have one problem, which I did not had using Clover.

When system boots I have opencore boot menu (text or Canopy) only with low resolution and 4:3 display support (very big icons). Also Apple Logo comes with low resolution. After boot, then the login screen comes totally garbled. Then when I put the system in standby and wake up, the screen is okay. (see attached screenshots).
The settings in MacOS for the monitor are 1080p@60Hz. Tried already several things but no luck. I must first go into standby and wake up to get proper screen after boot. I have no solution in combination with this monitor. Tried several settings in opencore config.plist - no help.
So I though it is a problem of this monitor, but why it is working, when going to standby and back?
Perhaps somebody can help me figure out the problem and solve it. Attached is also my opencore config.plist.

 

[dummybrain]

Hello,

switched my GA-Z77N-Wifi i7-3770S (F3 BIOS) from Clover 5119 to opencore 0.6.3 (Catalina 10.15.7). Everything is just working fine. The system is connected via HDMI to an ACER Predator XB271HU 27"-Display using the builtin HD4000 graphics. But still have one problem, which I did not had using Clover.

When system boots I have opencore boot menu (text or Canopy) only with low resolution and 4:3 display support (very big icons). Also Apple Logo comes with low resolution. After boot, then the login screen comes totally garbled. Then when I put the system in standby and wake up, the screen is okay. (see attached screenshots).
The settings in MacOS for the monitor are 1080p@60Hz. Tried already several things but no luck. I must first go into standby and wake up to get proper screen after boot. I have no solution in combination with this monitor. Tried several settings in opencore config.plist - no help.
So I though it is a problem of this monitor, but why it is working, when going to standby and back?
Perhaps somebody can help me figure out the problem and solve it. Attached is also my opencore config.plist.

you SMBIOS says iMac14,4 but the OC guide recommends 13,2 - maybe you could try that out. (your definition is for BigSur)

 

[mchammer26]

you SMBIOS says iMac14,4 but the OC guide recommends 13,2 - maybe you could try that out. (your definition is for BigSur)

This is only, because I want to install Big Sur. So big Sur is only supported with imac 14,4 or higher definition. Before I had MacMini 6,2 - the problem with GUI was the same with this definition. There is guide in opencore for big sure to use imac 14,4 for Big Sur.

Anyway, I think this is a frequency problem with the monitor. I checked now with a monitor connected with DVI. There the display is okay.

I will start playing around with EDID injection from linux into opencore. Perhaps this helps.

 

[dummybrain]

This is only, because I want to install Big Sur. So big Sur is only supported with imac 14,4 or higher definition. Before I had MacMini 6,2 - the problem with GUI was the same with this definition. There is guide in opencore for big sure to use imac 14,4 for Big Sur.

Anyway, I think this is a frequency problem with the monitor. I checked now with a monitor connected with DVI. There the display is okay.

I will start playing around with EDID injection from linux into opencore. Perhaps this helps.

Sorry, didn't know that - the screenshots made me assume that this is about Catalina and this is why I gave that reply. But may I kindly ask you to post your OC Efi folder? I'd be very thankful (of course with cleansed SMBIOS). And good luck with EDID injection as this is the level that is rocket science to me.

 

[squarecandy]

@mchammer26 did you ever get this resolved? Having the same issue with my GA-Z77N-Wifi - I know the montherboard HDMI only supports 1080p, but the only monitor I have here is 4k and it doesn't seem to want to play nice.

 

[mchammer26]

Hello,

I never got this resolved. I think it is a problem between my 4K monitor and the HD4000. I upgraded to OpenCore 0.6.9 and Big Sur now, but the problem with the garbled screen still exists after these upgrades.
Only way to fix this for me is going to standby and back. Then the screen is okay and everything is working.

 

[Westsurf]

@Robbish used SMBIOS14,4 to get Big Sur on his Z77 build. Whilst he doesn’t mention 4K screen I don’t believe he has the garbled screen issue.

Robbish Build

 

[Edhawk]

With 2nd and 3rd Generation Intel Core™ Processors the maximum supported resolutions are:

• DisplayPort 1.1 = 2560x1600 at 60 Hz
• HDMI 1.4 = 1920x1200 at 60 Hz
• DVI (Single-link) = 1920x1200 at 60 Hz

You might be able to get 4K resolution using a HD 4000 IGPU, but not @60Hz. The IGPU will struggle to initialise the display at the higher resolution and refresh rate. Does the System Preferences > Displays Preferences pane offer the option to change the refresh rate? Have you tried dropping the refresh rate down to 24Hz or 30Hz if either option is available .

Selecting the System Preferences > Displays - 'Default for Display' option might be part of the reason the screen is garbled before the sleep and wake happens. Does macOS automatically reduce the refresh rate or resolution after the sleep/wake?

Have you tried using a 'Scaled' resolution with a lower refresh rate?

To make full use of your 4K display you really need a discrete GPU. Obviously not an old one that lacks 4K support.

 

[mchammer26]

With 2nd and 3rd Generation Intel Core™ Processors the maximum supported resolutions are:

• DisplayPort 1.1 = 2560x1600 at 60 Hz
• HDMI 1.4 = 1920x1200 at 60 Hz
• DVI (Single-link) = 1920x1200 at 60 Hz

You might be able to get 4K resolution using a HD 4000 IGPU, but not @60Hz. The IGPU will struggle to initialise the display at the higher resolution and refresh rate. Does the System Preferences > Displays Preferences pane offer the option to change the refresh rate? Have you tried dropping the refresh rate down to 24Hz or 30Hz if either option is available .

Selecting the System Preferences > Displays - 'Default for Display' option might be part of the reason the screen is garbled before the sleep and wake happens. Does macOS automatically reduce the refresh rate or resolution after the sleep/wake?

Have you tried using a 'Scaled' resolution with a lower refresh rate?

To make full use of your 4K display you really need a discrete GPU. Obviously not an old one that lacks 4K support.

I can lower to 50 Hz on the Display options....... But 24/30 Hz is not offered. I will try to lower it to 50 Hz.... I come back to the thread. I need some time, because I upgraded to Opencore 0.7.0 yesterday and forgot to modify the config.plist for 0.7.0. So I first need to get my system running again....

 

[Robbish]

@Robbish used SMBIOS14,4 to get Big Sur on his Z77 build. Whilst he doesn’t mention 4K screen I don’t believe he has the garbled screen issue.

Robbish Build

Correct, all works well for me, I don't have a garbled screen issue but I don't own a 4K screen neither. I use DVI-D to a 1080p monitor and HDMI to a 720p TV (I know.. )