LG Ultrafine 5k at 5k? Help me out to find out.

Hey guys,

I'm a professional graphic designer looking to finally build a Hackintosh with a 5k display (LG Ultrafine 5k). I thought that I was finally found an easy solution by using the Gigabyte Z390 Designare which comes with built-in Titan Ridge card but sadly the display is not being driven at 5k, only 4k upscaled to 5k. Even if in macOS shows 5k resolution, I assure you it's working at 4k upscaled to 5k.

However @joevt (an user from another hackintosh forum) pointed out to check clocks on SwitchResX and execute a command for further analysis. He also said that even if the new 2019 LG display could be using DP1.4 the bandwidth won't be enough because this display is 10bits. In other words, you can do 5k@60hz 8bits with one DP1.4 port but you can't do 5k@60hz 10bits with just one stream. Quoting what he posted below:

For example, 5120x2880, 938.25 MHz, 10 bpc requires 28.15 Gbps but DisplayPort 1.4 maxes out at 25.92 Gbps. 8 bpc requires 22.52 Gbps. Dual DisplayPort 1.2 is 17.28 Gbps * 2 = 34.56 Gbps.

Turns out that even if the new 2019 LG Ultrafine 5k display is using Titan Ridge (that we're not sure) the required bandwidth won't be enough to drive it at full resolution and 10bits. Unless Apple/The display is applying some kind of compression or doing something else that we're not aware of.

That leave us with the requirement to have 2 DP inputs, something the Designare lacks even if it comes with the Titan Ridge built-in. You can only achieve it by using the Alpine or Titan Ridge AIC.

Please read here if you want to help! If you got the LG Ultrafine 5k and a setup where you are either using Titan Ridge or Alpine Ridge (both coming with 2 DP-in ports), would you please execute the command below? That will tell us how the streams are handled on macOS and see if it's working correctly at 5k native or really 4k upscaled to 5k.

/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > AGDCDiagnose_a.txt 2>&1

Upload the .txt file and I will analyse for you.

Thanks a lot!