[Solved] Anyone with an Ultrawide 34UC88 at 75Hz?

[20four80five]

I have been trying to get my LG-34UC88-B screen to run at 75Hz and it only shows 30Hz and 60Hz.

I have another drive with Windows 10 and can easily change the LG-34UC88 Refresh Rate to 75Hz. Confirm 75Hz using the UFO Test.

I have an AMD Sapphire Nitro RX570 graphics card using the Orinoco Framebuffer.

- I tried using carpentryplus25's guide here but I did not ending up needing to make any changes as the Orinoco FB is a perfect match for my graphics card.
- I have also tried my luck a few times with SwitchResX but I can only get it to 67Hz which doesn't make sense to me when it can run fine on Windows 10 at 75Hz. I've tried with and without my patched DSDT for my graphics card and 75Hz is still not an option.
- I've also looked into Display Overrides and have added in the appropriate DisplayVendorID-1e6d and DisplayProductID-76e4 with the correct matching values from the EDID file and that didn't change anything.
- I previously was using the 15,1 SMBIOS and now 18,3 but things remain the same.
- I've attached the EDID file for the LG-34UC88 from SwitchResX.

I would really like to get my LG-34UC88 running at 75Hz as 60Hz puts a lot of stress on my eyes after a few hours of working.
Any help would be greatly appreciated

 

[zakklol]

I've been running mine at 75Hz with my RX480, on both a 14,2 and 18,3 SMBIOS. With 14,2 I was running just RadeonDeinit + injectATI with Orinoco. With 18,3 I'm using Lilu+WhateverGreen, and I'd previously been using WhateverGreen with the 14,2 SMBIOS.

I've never had to do anything to enable 75Hz, it was always available. Maybe your issue is 570 specific? Seems odd.

 

[20four80five]

I've been running mine at 75Hz with my RX480, on both a 14,2 and 18,3 SMBIOS. With 14,2 I was running just RadeonDeinit + injectATI with Orinoco. With 18,3 I'm using Lilu+WhateverGreen, and I'd previously been using WhateverGreen with the 14,2 SMBIOS.

I've never had to do anything to enable 75Hz, it was always available. Maybe your issue is 570 specific? Seems odd.

Thanks for the reply @zakklol - happy holidays as well

This does seem like a strange one for sure. The fact that you have your 34UC88 running at 75Hz gives me some hope at least.

I've tried both, with Lilu+WhateverGreen and with RadeonDeInit, again, both didn't reveal the 75Hz option under System Prefs.

Are you connected via DisplayPort like I am? Are you using a patched DSDT?

Can you please post your results from Terminal for these commands:

1.

ioreg -l | grep "IODisplayEDID"

2.

ioreg -l | grep "IODisplayPrefsKey"

And if you can also attach your config.plist that would be amazing! I need to get this sorted out

Thanks!

 

[20four80five]

I've been running mine at 75Hz with my RX480, on both a 14,2 and 18,3 SMBIOS. With 14,2 I was running just RadeonDeinit + injectATI with Orinoco. With 18,3 I'm using Lilu+WhateverGreen, and I'd previously been using WhateverGreen with the 14,2 SMBIOS.

I've never had to do anything to enable 75Hz, it was always available. Maybe your issue is 570 specific? Seems odd.

Also, what does your DisplayVendorID-1e6d folder look like within your System/Library/Displays/Contents/Resources/Overrides/ folder. I am very much interested to see if I'm missing something from my end.

Thanks

 

[20four80five]

I've been running mine at 75Hz with my RX480, on both a 14,2 and 18,3 SMBIOS. With 14,2 I was running just RadeonDeinit + injectATI with Orinoco. With 18,3 I'm using Lilu+WhateverGreen, and I'd previously been using WhateverGreen with the 14,2 SMBIOS.

I've never had to do anything to enable 75Hz, it was always available. Maybe your issue is 570 specific? Seems odd.

Hey @zakklol - sorry for the ping, just wanted to know if you were able to help me out - I've been going at this for the past week trying all sorts of things with no luck.

 

[20four80five]

After many hours and reading just about everything to do with monitors, ioreg, EDID, CRU on Windows, Display Overrides, clover DSDT, injecting EDID, SwitchResX - it was just a simple matter of changing to the iMac14,2 SMBIOS - like wow, talk about TIL!

 

[Esau_Canto]

After many hours and reading just about everything to do with monitors, ioreg, EDID, CRU on Windows, Display Overrides, clover DSDT, injecting EDID, SwitchResX - it was just a simple matter of changing to the iMac14,2 SMBIOS - like wow, talk about TIL!

Did you have any problem activating the 75 Hz option. I bought a new monitor and the 75 option can be selected, but if I do it the screen goes off and says it has no signal. Besides changing the SMBIOS did you do something else? Any help is welcome.

 

[20four80five]

Did you have any problem activating the 75 Hz option. I bought a new monitor and the 75 option can be selected, but if I do it the screen goes off and says it has no signal. Besides changing the SMBIOS did you do something else? Any help is welcome.

No problems whatsoever.

What monitor did you get?

 

[Esau_Canto]

No problems whatsoever.

What monitor did you get?

Asus PB328Q. Now I can't used display port. I have to connect via HDMI :/

 

[20four80five]

Asus PB328Q. Now I can't used display port. I have to connect via HDMI :/

attach your EFI folder as a zip, I used to have an Nvidia graphics card so I can try to help but no guarantee.
Also, are you using the latest Nvidia web drivers?