Mac Pro 2019 (MacPro 2019) Display Settings Have No 5120x2160 Max Res For LG 34BK95U Monitor !

Did you press the [Option] / [Alt] / [⌥] button/key in your keyboard before clicking on the "◉ Scaled" option ?

then did you select the checkbox "✅ Show all resolutions" ?

... that shows all other available resolutions.

More info: Use one or more external displays with your Mac - Apple Support

( in above apple webpage, search for "option key")

Hi.

Please kindly read/scan + follow the steps mentioned by Apple support here and here.

( Use the TB cable that came with your LG monitor ).

LG UltraWide monitor model numbers:

LG 34BK95U - W

LG 34BK95U - WY

etc

This monitor supports following two types of max res (maximum resolution) :

(1) HDMI : 3440 x 1440.

(2) USB-C / Thunderbolt 3⚡/ DP : 5120 x 2160.

in macOS Monterey : click on main-menu  > System Preferences... ⚙ > Displays 🖥 > there you will see:

Resolution:

◉ Default for Display.

◎ Scaled.

Change above settings into below, select "Scaled":

Resolution:

◎ Default for Display.

◉ Scaled.

and "Scaled" option will auto-select the sub-option "Default" ( 2560x1080 ).

Now select right side other options, next to the "Default" sub-option:

• 3360x1417
• 3840x1620

Change color profile, into this: "Display P3".

In our/my case, (we also have same graphics/video card as yours),

we got max res 3840x1620 , not the 5120x2160.

The 3840x1620 res is still better than HDMI based max res : 3440x1440.

Please wait for others to post better solution.

And, if you read this page on Apple support site : Use the Radeon Pro W5500X MPX Module with your Mac Pro - Apple Support

then, you will know, this graphics/video card has these capabilities/options:

(1) When/if your computer has one/single W5500X graphics/video (MPX) card, then it can output:

(1a) max res 3840x2160 at 60 Hz via two HDMI ports, toward upto two 4K displays/monitors,

AND (any one of the below 3 options/capabilities):

(1b1) max res 3840x2160 at 60 Hz via two Thunderbolt3 ports, toward upto two 4K displays/monitors,

or

(1b2) max res 5120x2880 at 60 Hz via one Thunderbolt3 ports, toward upto one 5K display/monitor,

or

(1b3) max res 6016x3384 at 60 Hz via one Thunderbolt3 ports, toward upto one Apple Pro Display XDR display/monitor.

(2) When/if your computer has TWO/DUAL W5500X graphics/video (MPX) cards, then these two cards can output:

(2a) max res 3840x2160 at 60 Hz via four HDMI ports, toward upto four 4K displays/monitors,

AND (any one of the below 3 options/capabilities):

(2b1) max res 3840x2160 at 60 Hz via four Thunderbolt3 ports, toward upto four 4K displays/monitors,

or

(2b2) max res 5120x2880 at 60 Hz via two Thunderbolt3 ports, toward upto two 5K displays/monitors,

or

(2b3) max res 6016x3384 at 60 Hz via two Thunderbolt3 ports, toward upto two Apple Pro Display XDR displays/monitors.

in MacPro 2019, in top-rear side, there are two Thunderbolt 3 ports, when there is single card.

in MacPro 2019, in top-rear side, there are four Thunderbolt 3 ports, when there are two/dual cards.

so, even with a single card, this (W5500X) graphics/video card suppose to be able to output one 5k.