Super Ultra Wide on Mac

[Ulysses499]

Hey guys.

 

I treated myself to a Samsung CRG9 which should be able to do 10bit colour with a resolution of 5120x1440 at 100hz.

I have run into (it seems a common) problem where I can do everything but go over 60hz. 

Since Apple rated my MacBook to be 5k@60hz & 10bit capable, it should be possible.

If I lower the resolution to 1080p@32:9 I can go up to 120hz but at 1/4 of the resolution I am stuck again at 60hz. 

This is a sign for me that it has to be a software issue. I already tried cscreen with no result...

 

Does anyone have any tips?

 

I am running a 2019 13 inch MBP (the one with retina & touch-bar but only 2 usb c/thunderbolt 3 ports) and use a Thunderbolt 3 to DP 1.4 cable to connect.

 

If anyone has any ideas or tips I would love to hear from you

 

Have a great weekend my fellow tech nerds!

[DogKnight]

It is worthwhile checking your cables and adapters. 

 

I currently have a 15" 2019 MBP for work. I have it connected to an OWC Thunderbolt 3 dock via a thunderbolt 3 cable that can manage a full 40gb.  From the dock, I have a mini DisplayPort to HDMI active adapter. Then it uses a HDMI 2.1 cable to my display. 

 

I don't have a super ultrawide, but on my regular ultrawide (3440 x 1440) I am able to obtain 85hz. On a different monitor (1080p), I was able to hit the full 240hz of the display. 

The Ultrawide supports 160hz, but only via display port. And I have a PC connected to it via display port. For a work computer it wasn't a huge priority. 

 

The correct cables and adapters make a big difference in regard to resolutions and refresh rate. Check the specs for different HDMI / Displayport specs and whether or not your parts support the spec you want. Pretty sure there has been a Tech Quickie or LTT video on the subject. I have linked the parts I have used below. The dock is completely optional of course but being able to run just the one cable to the MBP is great. Full spec thunderbolt cables are pricey. And be aware that some MBP's only have two thunderbolt controllers shared among four ports. So by running devices off two ports on one side, you can decrease the available bandwidth. 

Dock: https://www.owcdigital.com/products/thunderbolt-3-dock-14-port
Adapter: https://www.alogic.co/us/alogic-ultra-mini-displayport-1-4-to-hdmi-2-0-adapter-4k-60hz-active-20cm.html
Thunderbolt Cable: https://www.startech.com/en-au/cables/tblt3mm2ma

Hope this info helps. 

[Ulysses499]

1 hour ago, DogKnight said:

It is worthwhile checking your cables and adapters. 

 

I currently have a 15" 2019 MBP for work. I have it connected to an OWC Thunderbolt 3 dock via a thunderbolt 3 cable that can manage a full 40gb.  From the dock, I have a mini DisplayPort to HDMI active adapter. Then it uses a HDMI 2.1 cable to my display. 

 

I don't have a super ultrawide, but on my regular ultrawide (3440 x 1440) I am able to obtain 85hz. On a different monitor (1080p), I was able to hit the full 240hz of the display. 

The Ultrawide supports 160hz, but only via display port. And I have a PC connected to it via display port. For a work computer it wasn't a huge priority. 

 

The correct cables and adapters make a big difference in regard to resolutions and refresh rate. Check the specs for different HDMI / Displayport specs and whether or not your parts support the spec you want. Pretty sure there has been a Tech Quickie or LTT video on the subject. I have linked the parts I have used below. The dock is completely optional of course but being able to run just the one cable to the MBP is great. Full spec thunderbolt cables are pricey. And be aware that some MBP's only have two thunderbolt controllers shared among four ports. So by running devices off two ports on one side, you can decrease the available bandwidth. 

Dock: https://www.owcdigital.com/products/thunderbolt-3-dock-14-port
Adapter: https://www.alogic.co/us/alogic-ultra-mini-displayport-1-4-to-hdmi-2-0-adapter-4k-60hz-active-20cm.html
Thunderbolt Cable: https://www.startech.com/en-au/cables/tblt3mm2ma

Hope this info helps. 

I might buy the dock later on because the one cable solution sounds pretty nice.

Cable wise I should be ready to go, here is one picture of the item description of my cable:

If it works for the new M1 Mac I don't see any reason it should not work on mine.

I tried out running in clamshell mode to see if a decreased GPU load would help to no avail...

The HDMI adapter sadly won't work since 5120x1440@120hz is like 5k@60hz.

 

On the Apple forums I read a lot about running the monitor in DP 1.2 mode instead of 1.4 but with a 1.4 cable, sadly this also did not work. 

I also find it super weird that at 1/4 resolution I also can't go beyond 60hz but on the higher 1080p in 32:9 format it is possible to select 120hz. 

 

It seems like some kind of mode is not activated that would allow for a "natural" resolution to go up to the full refresh rate capabilities.

 

Thank you for your shared experience though, this give me hope that somehow this is fixable!

[DogKnight]

So having a look on the product page for the monitor, the HDMI port on the monitor is only version 2.0. The display port version is listed as 1.4. 

Based off that, the HDMI output is pretty useless. The display port can either do the equivalent of 4k / 120hz, or 5k / 60hz. 

 

The cable you show appears to be capable of 32.4gbps bandwidth. 

According to a video bandwidth calculator (https://k.kramerav.com/support/bwcalculator.asp), 5120 x 1440 at 120hz should require 26.54Gbps bandwidth. 

So technically it should be possible. 

Mac OS isn't good at giving you many options regarding display resolutions and refresh rates. There are some apps on the App Store that allow you to specify custom values. It may take a little tweaking, but could be worth a try. 

 

Good luck!

[Ulysses499]

1 hour ago, DogKnight said:

So having a look on the product page for the monitor, the HDMI port on the monitor is only version 2.0. The display port version is listed as 1.4. 

Based off that, the HDMI output is pretty useless. The display port can either do the equivalent of 4k / 120hz, or 5k / 60hz. 

 

The cable you show appears to be capable of 32.4gbps bandwidth. 

According to a video bandwidth calculator (https://k.kramerav.com/support/bwcalculator.asp), 5120 x 1440 at 120hz should require 26.54Gbps bandwidth. 

So technically it should be possible. 

Mac OS isn't good at giving you many options regarding display resolutions and refresh rates. There are some apps on the App Store that allow you to specify custom values. It may take a little tweaking, but could be worth a try. 

 

Good luck!

Yeah, I used a terminal tool to try and force run 100hz or 120hz (120hz is only supported in 8bit colour mode by the display) but neither was accepted... 

You can run alternative resolutions on mac os by clicking control while pressing the scale radio button, but that does not help since I can select the correct resolution and this does not make other frame rates available.

From all the Apple forum discussions it seems to be a software error, but Apple is very silent about details.

I think it has to do with the driver implementation for the internal GPU. 

 

I would love to test an eGPU but I do not have an enclosure nor a supported gpu at hand.

I would also love to test an external 5k 60hz display to make sure the gpu would be able to handle this.

[DogKnight]

Frustrating for sure. 

If it ever does get resolved, try remember to add to this thread as I am sure others will come across the issue.

Hopefully they fix it sooner rather than later so you can enjoy that beautiful monitor. 

[Ulysses499]

On 4/1/2021 at 3:08 AM, DogKnight said:

Frustrating for sure. 

If it ever does get resolved, try remember to add to this thread as I am sure others will come across the issue.

Hopefully they fix it sooner rather than later so you can enjoy that beautiful monitor. 

Thank you ! If I solve this issue I will either post it in this thread or if this thread is too old by then maybe I will make a tutorial/recommendation