Samsung Neo G9 57" w/ M4 Max - HiDPI options

[cdeanatx]

Hi there!

I just got the brand new M4 Max Mac Studio and was super excited to be able to use my Samsung Neo G9 57" 32:9 monitor closer to its full potential. Previously, I had an M1 Pro MBP and the best I could do was 5120x1440 (non-HiDPI) @ 120Hz.

MacOS natively supports 7680x2160 @ 120Hz and 3840x1080 (HiDPI) @ 120Hz, but unfortunately it doesn't seem to support 5120x1440 (HiDPI) @ . I did some searching and found out about BetterDisplay, which I had hoped would solve my problem. I was able to add a custom resolution of 5120x1440 @ 120Hz but only for "low resolution" and not HiDPI.

With the current options available to me:

• 7680x2160 looks stunning and everything is super clear but tiny to the point that it's not really viable for apps without their own scaling features (including any native Mac OS menus or apps)
• 3840x1080 HiDPI also looks great (though maybe not as good as native) but has the opposite problem. Most UI elements, including native MacOS menus/apps, Chrome url/bookmarks bar, etc. are huge
• 5120x1440 low resolution is the Goldilocks of scaling but, without a HiDPI version, everything just looks fuzzy by comparison

What I'm wondering is this: Is this a result of hardware limitations or software limitations? If the latter, I would assume BetterDisplay will build out support to unlock these limitations. Really struggling with what to do here. Any advice would be welcome!

[waydabber]

It is a hardware limitation. You can enable 8K+ resolutions under Settings/Displays/Overview/Additional settings... and create a virtual screen, mirror it to your real screen and set it to 5120x1440 HiDPI as a workaround.

[kusokpnz]

hi, i use m3max and samsung 57. with virtual display and "mirror" and "over 8k" (betterdisplay option) modes you can use any resolution scaling with hidpi,120ghz,hdr. you can also use 2 cables and PBP mode. My main mode is hdmi<>hdmi, but i also tested usbС<>hdmi in one cable and it works too. (for 120ghz with usbC read: https://forums.macrumors.com/threads/dp-usb-c-thunderbolt-to-hdmi-2-1-4k-120hz-rgb4-4-4-10b-hdr-with-apple-silicon-m1-m4-now-possible.2381664/)

I found a convenient scaling for myself in this resolution:

  Displays:
virtual:
  Resolution:	12032 x 3384
  UI Looks like:	6016 x 1692 @ 120.00Hz
  Main Display:	Yes
  Mirror:	On
  Mirror Status:	Master Mirror
  Online:	Yes
  Rotation:	Supported
Odyssey G95NC:
  Resolution:	12032 x 3384
  UI Looks like:	6016 x 1692 @ 120.00Hz
  Mirror:	On
  Mirror Status:	Hardware Mirror
  Online:	Yes
  Rotation:	Supported
  Automatically Adjust Brightness:	No
  Television:	Yes

[cdeanatx]

Wow @kusokpnz this is exactly what I was looking for, thanks! My only issue is that my screen is flickering, so I'm wondering if maybe the HDMI cable I'm using isn't up to the task. Would you mind sharing with me the cable that you're currently using?

abc@def ~ % system_profiler SPDisplaysDataType
Graphics/Displays:

    Apple M4 Max:

      Chipset Model: Apple M4 Max
      Type: GPU
      Bus: Built-In
      Total Number of Cores: 32
      Vendor: Apple (0x106b)
      Metal Support: Metal 3
      Displays:
        ROG PG278Q:
          Resolution: 2560 x 1440 (QHD/WQHD - Wide Quad High Definition)
          UI Looks like: 2560 x 1440 @ 120.00Hz
          Main Display: Yes
          Mirror: Off
          Online: Yes
          Rotation: Supported
        Odyssey G95NC:
          Resolution: 12032 x 3384
          UI Looks like: 6016 x 1692 @ 120.00Hz
          Mirror: On
          Mirror Status: Hardware Mirror
          Online: Yes
          Rotation: Supported
          Television: Yes
        Virtual 32:9:
          Resolution: 12032 x 3384
          UI Looks like: 6016 x 1692 @ 120.00Hz
          Mirror: On
          Mirror Status: Master Mirror
          Online: Yes
          Rotation: Supported

[cdeanatx]

Hmm actually my HDMI cable is marked as "Ultra High Speed" which seems to be the highest quality available with 48Gbps of bandwidth. Now I'm wondering if it's the Variable Refresh Rate set for my Samsung 57 in MacOS display settings. I see it differs from what you have, but I have no other option available to me currently.

[kusokpnz]

There are also a lot of messages on different forums that there are many bugs in macOS when you go slightly above 4k and increased hertz. At least, we discussed the mirror problem here (#4123). And that for m4 they are also fixing it little by little in Sequoia. Try to reconfigure everything from default, play with different settings, in the worst case, update macOS to the latest. 120Hz worked for me on Sonoma, but I caught a bug using the above link. Also try setting it up without the second display first. And then connect it to eliminate any problems.

[cdeanatx]

Thanks so much for all your input. I’ll play around with things tomorrow and see if I can get the refresh rate locked in at 120 Hz and report back

[kusokpnz]

@cdeanatx
Today I switched the source between different PCs. When I returned to MacOS, VRR 48-60 turned on and nothing else was available. After rebooting, only 60 remained. Various settings could not select 120 fps. I deleted the virtual display and it became possible to select 120 at the standard resolution, then I recreated the virtual display and it already attached 120 to the monitor in mirror mode. Apparently, I will have to live with some inconveniences in some scenarios.

[cdeanatx]

@kusokpnz Yes, unfortunately this is the price we pay for crystal clear resolution with this monitor using MacOS. If it helps, this is the concise set of steps that I have found to reliably fix the reversion to VRR or 60 Hz:

1. Ensure Enforce virtual screen mirroring is turned off in the virtual display's Association settings
   1. This doesn't need to be done each time you have an issue. You can just set this once
2. Stop mirroring your G9 57 to the virtual display
3. In MacOS display settings, check what resolutions are available on your G9 57
   1. If 120 Hz is available, select it and enable mirror to the virtual display. You're done!
   2. If only VRR and/or 60 Hz is available, restart your computer
4. Once the computer boots up, the 120 Hz refresh rate should be available on your G9 57. Select it.
5. Reenable mirroring to the virtual display

While it is annoying to be sure, the above steps are actually very quick and easy, especially since MacOS's "reopen current windows" (or whatever it's called) feature works very well upon reboot.

[Chorizette]

Hello, I am not very techfriendly but I need to achieve the best setup with my macbook pro M4 and my neoG9 59' screen. So I did not get how you got these settings, I think the version of BetterDisplay has been updated since your answer. Could you help me please get through ? Thanks a lot !