Please help me connect LG monitor to 2015 MBP

[tosolu3]

I’m trying an LG 35WN65C ultrawide from Costco with my 2015 MBP in clamshell mode and am so confused about ports/adopters. The only cable provided that seems to work is HDMI to HDMI, but I keep getting a message to use the provided input cable. I also thought I read here that using thunderbolt would improve performance. If that’s true, what adapter would I need? I am utterly lost and am sure this is so simple to do. Thank you!

 

[joevt]

Why do you have a screenshot of a Thunderbolt 2 MacBook Pro specs?

Your 35WN65C seems to match the one at
https://www.lg.com/ca_en/desktop-monitors/lg-35wn65c-b#
but not the one at
https://www.lg.com/hk_en/monitor/lg-35wn65c-b#

If yours doesn't have a USB-C port or a Thunderbolt port, then use a USB-C to DisplayPort cable.

 

[tosolu3]

Those are the ports on my 2015 MBP. Sorry. Typo previously.

 

[justashooter]

On the back of the monitor in your picture you have DP-IN, that is displayport in, get a mini displayport to displayport cable such as this https://www.amazon.com/Cable-Matters-Mini-DisplayPort-Black/dp/B00C7RJQPY , which connects to the thunderbolt port on the MBP. But I don't believe your MBP will drive the 3440 x 1440 resolution of that LG Monitor. The specs for the 2015 at https://support.apple.com/kb/sp719?locale=en_US says it supports a maximum of 2880x1800

 

[joevt]

Those are the ports on my 2015 MBP. Sorry. Typo previously.

If you have a 2015 MBP instead of a 2016 MBP, then can you change the title of this thread?

The HDMI port of the 2015 MBP can only do 4K30 so you'll want to use one of the Thunderbolt 2 ports instead as @justashooter suggested.

On the back of the monitor in your picture you have DP-IN, that is displayport in, get a mini displayport to displayport cable such as this https://www.amazon.com/Cable-Matters-Mini-DisplayPort-Black/dp/B00C7RJQPY, which connects to the thunderbolt port on the MBP. But I don't believe your MBP will drive the 3440 x 1440 resolution of that LG Monitor. The specs for the 2015 at https://support.apple.com/kb/sp719?locale=en_US says it supports a maximum of 2880x1800

2880x1800 is for the laptop display. The Thunderbolt 2 ports can do 4K60.

 

[justashooter]

If you have a 2015 MBP instead of a 2016 MBP, then can you change the title of this thread?

The HDMI port of the 2015 MBP can only do 4K30 so you'll want to use one of the Thunderbolt 2 ports instead as @justashooter suggested.


2880x1800 is for the laptop display. The Thunderbolt 2 ports can do 4K60.

Guess I should read to the bottom of the spec sheet.

 

[tosolu3]

Thank you both for helping. A friend had a cable like the one you suggested - it's about 10 years old, but it works.

I'm able to choose 3440 x 1440 in my settings. The monitor's DisplayPort specs say 100Hz, and I'm able to choose 84.88, 60 or 55.

I'm not a gamer and only trying this (from a 27") to have more space for multiple documents while logged into a remote desktop. Feeling a little nauseated already (I'm super sensitive) so I'm not sure if the curved ultrawide is for me. Was hoping to avoid needing two monitors.

 

[joevt]

Thank you both for helping. A friend had a cable like the one you suggested - it's about 10 years old, but it works.

I'm able to choose 3440 x 1440 in my settings. The monitor's DisplayPort specs say 100Hz, and I'm able to choose 84.88, 60 or 55.

I'm not a gamer and only trying this (from a 27") to have more space for multiple documents while logged into a remote desktop. Feeling a little nauseated already (I'm super sensitive) so I'm not sure if the curved ultrawide is for me. Was hoping to avoid needing two monitors.

If you can do 4K60 then 3440x1440@100Hz should be possible as well. What does SwitchResX say?

 

[tosolu3]

I'm not familiar with SwitchResX, but downloaded the free trial. It doesn't show anything higher than 84.88.

 

[joevt]

Are you still using HDMI? I said the HDMI port of the MacBook Pro 2015 can only do 4K30. Connect the display using a mini DisplayPort to DisplayPort cable.

In SwitchResX, select "Show frequencies separated" and "Show best resolutions for display in bold".

Compress the output of the following command and attach (do it for HDMI also - choose a different filename for each):
/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > AGDCDiagnose_LG35WN65C_DP.txt 2>&1