JimHardy
Level 1 (29 points)
Apple TV

Q: Screen sharing resolution issues

I use a Late 2014 Mini (1.4 GHZ I5) as a media server with a HDTV as its display.  In the past, the Mac would remember the 1080p resolution of the display, even when the TV was turned off and I relied on Screen Sharing to control the system.  Recently, the Mac forgets about the 1080p resolution and only shows 1280 x 1024 and 1024 x 768 as options.  Oddly, a second, older similarly configured Mini that I use the same way remembers the 1080p resolution with no issues.

 

Any suggestions.

Mac mini (Late 2014), OS X Yosemite (10.10), 2.6 GHz, 8 GB RAM

Posted on Mar 31, 2016 2:10 AM

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JimHardy

Q: Screen sharing resolution issues

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  • by John Lockwood,

    John Lockwood John Lockwood Mar 31, 2016 2:29 AM in response to JimHardy
    Level 6 (9,349 points)
    Servers Enterprise
    Mar 31, 2016 2:29 AM in response to JimHardy

    It is typical for headless Macs like the Mac mini or Mac Pro to revert to lower resolution settings when they do not see a real monitor connected. What you may not be aware of is that at the same time the Mac will 'turn off' the video chip and revert to a software emulation of a screen which also significantly reduces video performance including for Screen Sharing.

     

    If the Mac is being used in a Media Center type setting then the solution is to use a device like this one http://www.gefen.com/kvm/ext-hd-edidpn.jsp?prod_id=14859 which learns the signal from the real TV/monitor and thereafter will keep sending this signal to the Mac even if the TV/monitor is turned off or physically disconnected.

     

    If the Mac is being used purely as a headless server and will not need to connect to a real TV/monitor then one of these devices will be a cheaper solution, see - http://www.fit-pc.com/web/products/fit-headless/

     

    Note: In both cases there will be other brands that do a similar job.

  • by JimHardy,

    JimHardy JimHardy Mar 31, 2016 2:35 AM in response to John Lockwood
    Level 1 (29 points)
    Apple TV
    Mar 31, 2016 2:35 AM in response to John Lockwood

    That's odd because screen sharing at 1080p resolution when the HDTV was turned off (but still connected) worked just fine for a year or so and still works on a second system. 

     

    I sure hope there are other options because, while I appreciate your advice, it's a rather expensive solution for a relatively minor problem.

  • by John Lockwood,

    John Lockwood John Lockwood Mar 31, 2016 2:54 AM in response to JimHardy
    Level 6 (9,349 points)
    Servers Enterprise
    Mar 31, 2016 2:54 AM in response to JimHardy

    I cannot answer why it used to work, maybe the TV was in sleep mode and not really turned off and this was enough for the Mac to still 'see' it.

     

    I bought a second hand HDMI Detective via eBay and it works great for my similar situation, as I mentioned there will be other cheaper equivalents. Try searching for something like EDID emulator or EDID headless.