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MatthewNYC

macrumors newbie
Original poster
Aug 9, 2019
1
0
Hi,

I have a mid 2015 Macbook Pro and I just received the:

49" CRG9 Dual QHD Curved QLED Gaming Monitor (model number LC49RG90SSNXZA).

The monitor is working, however, I get the following message on startup:

The optimal resolution for this monitor is as follows:

5120 x 1440 60Hz

Current Resolution: 3840 x 1080

I went System Preferences / Display / Resolution / Scaled /

and it set to "More Space" which is the highest resolution.

This article states that 4k is supported on my laptop but I"m not seeing any way to increase the resolution:

https://support.apple.com/en-us/HT206587

What do I have to do to be able to use the full 5120 x 1440 on the Samsung monitor using my Macbook Pro?

Looking forward to your reply.

Matthew
 

Rockadile

macrumors 6502a
Jun 11, 2012
501
210
Hi,

I have a mid 2015 Macbook Pro and I just received the:

49" CRG9 Dual QHD Curved QLED Gaming Monitor (model number LC49RG90SSNXZA).

The monitor is working, however, I get the following message on startup:

The optimal resolution for this monitor is as follows:

5120 x 1440 60Hz

Current Resolution: 3840 x 1080

I went System Preferences / Display / Resolution / Scaled /

and it set to "More Space" which is the highest resolution.

This article states that 4k is supported on my laptop but I"m not seeing any way to increase the resolution:

https://support.apple.com/en-us/HT206587

What do I have to do to be able to use the full 5120 x 1440 on the Samsung monitor using my Macbook Pro?

Looking forward to your reply.

Matthew
I don't think 2015 MBP can output 5120 x 1440. Specs says up to 4K and it has thunderbolt 2.

I'd assume you need a thunderbolt 3 Mac that can output up to 5K (5120 × 2880) to get a lower 5120 x 1440 option.

4K is 3840 x 2160 - 16:9 aspect ratio. Your monitor is 32:9.
 
Last edited:

Moonjumper

macrumors 68030
Jun 20, 2009
2,750
2,937
Lincoln, UK
I’ve read someone has managed that by connecting 2 cables and get the screen to be treated as 2 2560x1440 monitors that appear as one.

Another alternative is to see if you can get SwitchResX to do it. It has a 10 day trial period.
 
Jan 7, 2020
1
0
I have the same issue as the author, but my MBP is 2017 year and it is capable to output the pseudo 5K. But still monitor writes that it has the resolution of 3840x1080
DEC0FB06-FA2C-4317-92FE-FB8FB8B8A0AA.jpeg
DEC0FB06-FA2C-4317-92FE-FB8FB8B8A0AA.jpeg
737373CE-C2F4-404D-A221-ED1DB8359AA2.jpeg
 

joevt

macrumors 604
Jun 21, 2012
6,979
4,267
Does the MacBook Pro have AMD graphics or only Intel graphics?

Intel graphics cannot output resolution width greater than 4096 using macOS driver. It can in Windows. I guess Apple was lazy with the Mac driver. It is able to do 5120x2880 on displays that use a dual DisplayPort 1.2 HBR2 connections (LG UltraFine 5K, Dell UP2715K).
You can use the AGDCDiagnose command to see the connection(s) to a display. Each port of a display may have a different EDID. Some display settings can modify the EDID.

The new MacBook Air 2020 with Intel Gen11 graphics does support resolution widths higher than 4K. It also supports DisplayPort 1.4 and DSC. I wonder if this update (10.15.4) affects older Intel graphics? Probably not.

AMD should be able to do single connection 5120 wide. I think 10.15.4 made a change for that. Before 10.15.4, you could fix the problem by going into SwitchResX and selecting Scaled Resolution Base to 5120x1440. AMD on Mac Pro 2013 might have a problem though.
 

chabig

macrumors G4
Sep 6, 2002
11,461
9,328
Intel graphics cannot output resolution width greater than 4096 using macOS driver.
Apple’s tech specs say it can drive a single external display at up to 5120 x 2880 in addition to the internal display.

 

joevt

macrumors 604
Jun 21, 2012
6,979
4,267
Apple’s tech specs say it can drive a single external display at up to 5120 x 2880 in addition to the internal display.
Apple tech specs does not tell you that 5120 x 2880 only refers to such displays that use a dual DisplayPort 1.2 HBR2 connection (two tiles of 2560x2880).
A single cable display supporting 5120 x 2880 such as the iiyama PROLITE XB2779QQS-S1 is not supported.

There are some Apple tech support documents that refer to these displays as dual link SST:

But sometimes they don't mention the dual link requirement:

They mention a multi-cable 4K display but I don't think there is such a thing? They could mean 4K MST - but you should be able to connect two of those to a single Thunderbolt bus (MST is two streams over a single DisplayPort connection - this is different than two DisplayPort SST connections). They probably meant multi-cable 5K display (like the Dell UP2715K).

Here's an article they removed that mentions dual cable displays - dual cable uses two DisplayPort cables instead of a single Thunderbolt 3 cable (for dual link SST).
 
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