Make 1280×720 HiDPI Work on a 16:9 WQHD Display

Problem

1280×720 HiDPI mode does not work using SwitchResX, RDM or similar utility with an external monitor on a Retina MacBook Pro.

Solution

Use a custom scaled resolution with SwitchResX as a work around.

SwitchResX allows you to add custom “Retina” resolutions by adding exactly double the horizontal and vertical values of the desired HiDPI resolution.

Here’s a table that will achieve common 16:9 resolutions:

Desired 16:9 Resolution 2x SwitchResX Custom Resolution
1280×720 2558×1440*
1600×900 3200×1800
1920×1080 3840×2160

*Due to a feature of OS X 10.10 Yosemite, use the given value for a 1279×720 approximate resolution.  You could also use 2562×1440 for 1281×1440, but 1280×720 doesn’t work.

With a 2560×1440 display, 1280×720 yields the truest HiDPI result because it’s a 4:1 pixel mapping.  It looks great on a 25″ WQHD display.  The in-between resolutions might yield acceptable results, but for me there were some slight yet noticeable artifacts that disappeared at 1280×720.

 

6 thoughts on “Make 1280×720 HiDPI Work on a 16:9 WQHD Display

  1. Hi, I did exactly as you suggested regarding the desired resolution of 1280*720 HiDPI (scaled custom resolution of 2558*1440). However, even though the Status now is “Active” and correctly showing up in the list under “Current Resolutions”, it doesn’t give me HiDPI, nor does it appear an HiPDI text in the HiPDI field next to the selected resolution.
    I should also say that I’m currently trying to use this guide on a MacBook 12″ 2015 and a Dell U2515H combo. I guess it doesn’t matter should it be a rMBP as in this guide or a MB 12″?

    What gives? Cheers!
    Christer

  2. Christer — I ended up giving up on SwitchResX after upgrading to El Capitan. Instead, there were some technical gymnastics to get HiDPI working with the RDM tool on the Retina MacBook Pro Mid-2012.

    IOReg was used to get the very specific DisplayProductID hex value used to create the filename below (different versions of the U2515H have different DisplayProductID’s).


    /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-10ac/DisplayProductID-d06f

    Then I created the following file contents based on trial and error using disparate internet sources. It works on the rMBP Mid-2012, but might not work for your chipset.


    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
    <plist version="1.0">
    <dict>
    <key>DisplayProductName</key>
    <string>Dell HiDPI U2515H</string>
    <key>DisplayProductID</key>
    <integer>53359</integer>
    <key>DisplayVendorID</key>
    <integer>4268</integer>
    <key>scale-resolutions</key>
    <array>
    <data>AAAKAAAABaAAAAABACAAAA==</data>
    <data>AAAFAAAAAtAAAAABACAAAA==</data>
    <data>AAAPAAAACHAAAAABACAAAA==</data>
    <data>AAAHgAAABDgAAAABACAAAA==</data>
    <data>AAAMgAAABwgAAAABACAAAA==</data>
    <data>AAAGQAAAA4QAAAABACAAAA==</data>
    <data>AAAKAgAABaAAAAABACAAAA==</data>
    <data>AAAKrAAABgAAAAABACAAAA==</data>
    <data>AAAFVgAAAwAAAAABACAAAA==</data>
    </array>
    </dict>
    </plist>

    Let me know if you figure out a solution that works.

  3. Has someone figured this out yet for DELL U2515H? I have a 2015 MacBook Pro 15″ and I can only get 16:10 resolutions like 1920×1200 work in HiDPI with RDM on the U2515H.

    Here is some nice tool I wrote to quickly paste an existing PropertyList file (like the one above) and see the resolutions.
    It also works the other way round. You can add custom resolutions and generate a PropertyList file.

    https://comsysto.github.io/Display-Override-PropertyList-File-Parser-and-Generator-with-HiDPI-Support-For-Scaled-Resolutions/

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