MP 7,1 New Mac Pro 7,1 and 34WK95U-W (LG Ultrawide) Display problems

[typecase]

Hello All,

I received my Mac Pro 7,1 last night. While I'm excited about this beast there has been a lot of growing pains. The first of which is that my Mac Pro 5,1 worked great with the 34WK95U-W (LG Ultrawide) at 5120 x 2160 with 'retina' resolutions with a Sapphire RX580 over displayport. The new Mac Pro won't display the full resolution over HDMI (which is the only ports included with the RX5500 that came with the computer). Is this a problem with my cable or is this simply not capable of sending the full resolution over HDMI? The full resolution is displayed over thunderbolt 3 but I'd rather not use the ports if I don't have to. Any help appreciated.

 

[gabrielefx]

Hi,
you can use your LG monitor with the thunderbold 3 cable, I have the same model but you need an MPX AMD gpu, the basic one is ok (580X) or you need a gpu with a displayport output. HDMI is not enough for a 5120x2160 60Hz resolution.
There is an issue with our LG monitor, you can't enable HDR using the tb3 cable, it works only on the displayport input. I purchased a thunderbolt 3 to displayport cable.

 

[typecase]

Thanks. So I guess this means I can't use any of the ports on the card. I wonder if Apple will allow me to swap this card for the 5700 for whatever the price difference is.

 

[XNorth]

Can't you use the TB ports on top of the 7.1, per this Apple support page? https://support.apple.com/en-us/HT210957

I have the B version of the same monitor. MBP 16" connected with TB 3; MP 5,1 connected with DisplayPort. Both at 5120 x 2160, 60Hz. Make sure displayport is set to version 1.2 on the LG.

HDR is available with DP version 1.4, but color and resolution is degraded compared to the LG set to DP v1.2 and "HDR effect" Picture Mode

 

[typecase]

Can't you use the TB ports on top of the 7.1, per this Apple support page? https://support.apple.com/en-us/HT210957

I have the B version of the same monitor. MBP 16" connected with TB 3; MP 5,1 connected with DisplayPort. Both at 5120 x 2160, 60Hz. Make sure displayport is set to version 1.2 on the LG.

HDR is available with DP version 1.4, but color and resolution is degraded compared to the LG set to DP v1.2 and "HDR effect" Picture Mode

I am using the ones on the I/O card now. I was just hoping to use the ports on the card so I could free up the others in case. Kinda stupid that the bottom two cards ship with HDMI ports only.

Thanks for the link too. It confirms what I had thought through Apple directly. Very helpful.