I have a MacBook Pro 2016 (with Thunderbolt 3 ports on macOS 10.13.6) and I need an external display. I bought an ASUS VP28U (4K), connected it with an HDMI to USB-C adapter and, generally, it works. The problem is that everything is super-small, I guess because of the 4K.

Why doesn’t this display have any scaling option? or... How can I adjust the scaling of an external display while still using the full 4K resolution quality? The only options given to me were to reduce it to 1080p, with obvious results...

Am I making something wrong? Using the wrong cables? Missing some options?

Or is the display a bad one? Anyone with experience with my same configuration may help in sharing his setup?

Thank you

  • does the monitor has any settings for that ?
    – Ruskes
    Nov 14, 2018 at 23:55
  • 1
    Nope...! That’s what surprised me! No control button on the frame as my previous 1080p display had... I wonder if it is Mac & HDMI not being friends and needing DisplayPort, but I have really no idea about that, therefore I asked for help. Nov 15, 2018 at 7:11
  • I have a MacBook Pro Retina 13-inch late 2012. For me (and it sounds like what is happening in most of the other answers below) the ASUS VP28U is not being detected as a 4k monitor. My MacBook should be able to display 4k at 30Hz, but I don't get that option. When I select 1920 x 1080 the display is NOT scaled (i.e. the resolution doesn't look great) and the monitor itself (press the rear menu button twice) says it is being driven at 1920 x 1080.
    – MikeBeaton
    Apr 3, 2020 at 18:25

6 Answers 6


You need to set it to 1080p in order to get the scaling. A bit counter-intuitive this actually means that the display is using the full 4k resolution, but font sizes, window decorations, etc. is scaled to have the same size as with a 1080p display. This is what Apple calls "Retina Mode": Video, photos, etc. will display in their full resolution.

So try setting it to 1080p and then check on your monitor's on screen display that the incoming signal is actually 4k!

Note that the list of resolution in System Preferences > Display will also contain resolutions such as "1920 x 1080 (low resolution)". The added "(low resolution)" means that these are actual 1920x1080 resolutions, and not scaled like in Retina Mode.

If you do not see the list of resolutions, then hold down the Option-key and click the "Scaled" radio-button besides "Resolution:".

  • Thank you! There is indeed an 1080p option and, upon selecting it, the scaling works, but the sharpness is non existent. I avoided all the other (low res) options. At this point it must be the quality of the monitor. Nov 15, 2018 at 9:39
  • @NeeratheWildMage Did you check what the monitor's OSD says? I.e. which resolution is it detecting?
    – jksoegaard
    Nov 15, 2018 at 9:39
  • The amount of options was pretty scarce... where may I have found it? Edit: there is no button on the frame to access any OSD, now that I look at it... no nothing... Nov 15, 2018 at 9:41
  • 4
    When I set my external 2560x1440 display to 1080p or 720p or any other resolution on the list, a 1080p (or whatever I selected) signal is all that is sent and everything becomes pixellated.
    – Sparr
    Apr 30, 2020 at 17:08
  • 1
    EXCEPT 2048x1152 does scaling! Every other lower resolution sends the selected resolution, but 2048x1152 sends 2560x1440 with scaling. Entirely invisible to the user, but the OSD on the monitor clued me in. Thanks for the tip!
    – Sparr
    Apr 30, 2020 at 17:14

I tried RDM and SwitchResX but wasn't able to get a non-blurry scaled resolution for my display (1440p, HDMI).

But, now there is a new tool available: Github - BetterDummy. It handles all this much better by simulating a display with a certain aspect ratio that can then be duplicated on the actual display in the system settings (something some people achieved by buying actual 4k HDMI adapters in the past). This enables scaled "retina" resolutions for any display as far as I know.

Also, both Intel and Apple Silicon Macs are supported as well as macOS Monterey. List of aspect ratios of BetterDummy

See the README on Github for a more detailed explanation and any updates.

  • This definitely looks like the correct answer at this time Dec 14, 2021 at 19:47

You want something like this, right?!

enter image description here

Main ways to get this result:

  • Use a Mini Display Port (i.e. thunderbolt) to DisplayPort connector, not an HDMI to HDMI connector - you will likely see a lot more available resolutions (i.e. everything above 1920x1080 aka 1080p) if you have a hi-res (e.g. 4k) monitor
  • Use SwitchResX. It is quite fiddly to use, but it opens up a bunch of resolutions which your monitor supports but which Mac OS hides by default
    • You can also use it to add additional Scaled resolutions (same as scaling on your retina display, i.e. they don't change the available underlying screen resolutions, but they do change the apparent space on the screen)
    • And you can even add Custom screen resolutions, but these are super-advanced and probably not what you need!
  • A simpler rough equivalent to SwitchResX, but it won't give you as many options, is RDM which can be installed via a download linked from the GitHub page, or via Brew (brew install avibrazil-rdm).

The above lets you have a LOT more control over the real estate on your external monitor, and then - as you no doubt already know - you can also scale the internal MacBook LCD display:

enter image description here

Combine these. Try dragging some medium size window back and forth between the external monitor and the laptop screen - using all the above, you should be able to find scaling settings which make the sizes match while still giving you a lot of space for your app windows, so no cursor jumps!

PS This repeats this answer, since I believe the same info applies to both open questions.

  • 3
    RDM tool saved my day! Ty Jun 23, 2020 at 4:14

I needed to option-click ( on keyboard) Scaled to make 1920 x 1080[sic] available and select it to get the a different size scaling.


I cannot recommend 1080p which rendered unsharp, nor any setting with 'low resolution' except for the small but crispy clear 3860x2160 (low resolution)

Actually very counter-intuitive, indeed.


I had the same problem, so I used a new ANKER USB-C-to-HDMI adapter and it worked.

  • How exactly did this cable help? Pls provide more details. What was not working in your case and what were you able to do after using this cable? Which cable did you use before?
    – Alper
    Sep 21, 2022 at 17:03

Using an Active HDMI adapter did the trick for me, most of the ones for sale are passive and for some reason don't work with macOS scaling.

This blog goes into some more detail on it: https://cyberhost.uk/macos-monitor

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