External display scaling

Just chipping in my solution to this. First off, don't expect a Mac to behave well with external devices. I've had issues for YEARS with all sorts of things.

The work around for the High-Sierra OS bug in this case was related to the cable used in my case. It seems the old Thunderbolt ports on the left hand side of my MacBook got a downgrade from Yosemite to High Sierra. Switching to a standard, $5 HDMI cable and plugging it in on the right hand side of my Mac solved the problem.

I have had the same issue since beta and still no word from apple. They have seriously borked the display drivers. I run two Dell P2715Q monitors. One monitor allows me to choose the old scaling with all the previously supported resolutions from 1080p up to 4k. On 10.11 I was able to select the same resolutions on both monitors. Now I'm stuck with the resolutions you mentioned on my second monitor. If I put my MBP to sleep and wake it up both monitors reflect the resolutions you show with no in-between options between 1080p and 4k.

I have the same issue with an Asus MG279Q. It's a 2560x1440 monitor and after upgrading to Sierra my only resolution options in Displays are 720p, 1080p, and 1600x900. Worked fine at the native resolution before.

I'm having the same problem with my 4k Lenovo LEN LI2821wA and 13" 2015 MacBook Pro. Oddly whenever I use a thunderbolt 2 to display port cable, the scaling only offers 4k and 1080p. But using an HDMI connection I get the 2560 x 1440 resolution I prefer on my monitor. Really hope this problem is resolved soon

I'm having the same issue on my Lg 29" Ultra Wide monitor. The native resolution is 2560x1080 which was perfect under OSX EL Capitan but is missing from Sierra. It's bumped the monitor down to 1080P which looks horrible.

Same is happening to me. Here is how my options looks like, I don't have any options between 3840x2160 and 1920x1080.

Hope this gets fixed soon. It's affecting my work capability considerably.

I also have this issue with my 27" 1440p display (Acer XB271HU), it work perfectly fine over HDMI with a resolution of 2560x1440 until I updated to macOS Sierra yesterday. I now have to use my display in a horrible 1080p resolution where everything is blurry.
I Hope this gets fixed soon. It's also affecting my work capability considerably.

Same issue here. Mid-2014 MacBook Pro and Acer B286HK over DisplayPort. Worked with El Capitan, but in Sierra my only resolution options are:

3840x2160

1920x1080

1680x945

1600x900

1504x846

1280x720

1152x648

Fix this Apple!

I am having the exact same issue with my Dell P2715Q

I downloaded the .1 beta and just finished installing it. Can confirm the problem still exists.

Was anyone able to fix this?

A word from someone at Apple would be appreciated.

I could make my LG ultrawide monitor work properly with SwitchResX, but after 2 more steps:

1 - I disabled System Integrity Protection before installing SwitchResX (http://www.madrau.com/support/support/srx_1011.html)

2 - I created a custom resolution based on the 1080P60 (automatically detected), just changing the first resolution parameter from 1920 to 2560 (don't forget to save and reboot the computer after creating the custom resolution - check the status column next to the resolution created). Those are the parameters of the custom resolution:

I've been searching and trying fix this problem for three days, after upgrading to Sierra. I hope it helps!!

Same thing just happened to me. I have Sierra on one of my Macs and tried out connecting it to my 1440 display and it only goes up to 1080. My other laptop running El Capitan works just fine. This issue is NOT resolved in the 10.12.1 Beta update.

One way to fix this is to use an Active mDP to HDMI adapter and connect it the Thunderbolt 2/mDP of my Macbook Pro and it can now display at 2560x1440. So with Sierra installed, the HDMI on my Mac is useless if I want to use anything higher than 1080p. Super annoying.