lorax1284
Level 1 (4 points)
Desktops

Q: Using a UHD display with a Mac Mini via 1080pKVM

It seems that my new UHD TV is telling my Mac Mini it's a UHD display, and my Mac Mini won't take "yes" for an answer.

 

That is, I want to connect my Mac Mini through a KVM with three other (windows) computers to switch between them. I don't want the Mac Mini to detect that there is a UHD TV connected, and just display / send 1920 x 1080 60hz signal through my KVM to the UHD TV. My two Windows computers work fine with it.

 

Is there a way to set a Mac Mini not to "scale" the display to 1920 x 1080, but to just OUTPUT standard 1920 x 1080 60Hz signal?

 

Thanks in advance.

Mac mini, OS X El Capitan (10.11.6), Late 2014 i5

Posted on Sep 10, 2016 4:31 PM

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lorax1284

Q: Using a UHD display with a Mac Mini via 1080pKVM

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  • by lllaass,

    lllaass lllaass Sep 11, 2016 1:12 AM in response to lorax1284
    Level 10 (188,114 points)
    Desktops
    Sep 11, 2016 1:12 AM in response to lorax1284

    I do not understand what the difference is between a scaled 1080p and 1080p on a UHD screen.

  • by lorax1284,

    lorax1284 lorax1284 Sep 11, 2016 1:19 AM in response to lllaass
    Level 1 (4 points)
    Desktops
    Sep 11, 2016 1:19 AM in response to lllaass

    One thing I did discover: hold the "Option" button when clicking on the "Scaled" radio button on the "Display" settings panel, and more options appear in the list.

     

    When I choose "1920 x 1080" I'm offered only 30 Hz for the refresh rate (this is one of the options available without holding "Option" while clicking "Scaling".

     

    When I choose from the extended list the "1080p" option, I can also choose the refresh rate to 60 Hz... but neither the "1920 x 1080" setting nor "1080p" setting send a single that will pass through my KVM switch (the TV says "no signal present")

  • by Randy Decker,

    Randy Decker Randy Decker Sep 11, 2016 8:23 PM in response to lorax1284
    Level 1 (126 points)
    Apple Music
    Sep 11, 2016 8:23 PM in response to lorax1284

    Have you tried connecting directly from your Mac Mini to your UHD TV via HDMI?

  • by lorax1284,

    lorax1284 lorax1284 Sep 11, 2016 8:49 PM in response to Randy Decker
    Level 1 (4 points)
    Desktops
    Sep 11, 2016 8:49 PM in response to Randy Decker

    Yes, I have tried that, and I can get a 4K 30 Hz signal via direct HDMI to display on the UHD TV... but my need is to get any 1080p signal to pass through my KVM like my Windows computers do.

  • by Randy Decker,

    Randy Decker Randy Decker Sep 11, 2016 10:13 PM in response to lorax1284
    Level 1 (126 points)
    Apple Music
    Sep 11, 2016 10:13 PM in response to lorax1284

    I don't mean to vex you but why do you need to get the signal to pass though the KVM? It seems that the KVM is a problem. It seems that you have a complex setup. I'd like to learn more about it.

  • by lorax1284,

    lorax1284 lorax1284 Sep 12, 2016 5:52 AM in response to Randy Decker
    Level 1 (4 points)
    Desktops
    Sep 12, 2016 5:52 AM in response to Randy Decker

    I have 3 computers at my desk: main Windows machine, secondary windows machine, and Mac Mini. My main windows machine is where all my email and "productivity" apps are.

     

    I Want to be able to quickly and efficiently switch between the Mac as I can with Windows: sometimes there is a fourth machine, and AMD-based Windows ultra book, that also has no problem with this. The Mac worked fine when it was a 1080p screen. Now that it is a UHD screen, only the Mac is unable to fully participate in this arrangement.

     

    I am using a workaround where I switch to the Mac on the KVM then manually switch input ports on the TV to see the Mac screen, but since all my email and bookmarks etc at on the Windows PC I have to switch back often and it is annoying to have to switch the TV manually every time.

     

    The Mac is doing a wonderful job handshaking with the UHD TV to determine its abilities... The display settings dialog even says "Samsung" (where it used to say "LG" with the 1080p screen) I wonder if it can be made to stop doing that and be made to send the same signal it sent to the other TV that was fine with the KVM.

     

    THe KVM is the Belkin 4 port SOHO unit that is black with the large round buttons on the front. The Mac Mini is connected to the switch via HDMI to DVI cable (which worked with a 1080p TV).