2017 iMac 27" i7 dual display

Discussion in 'iMac' started by Schmidtsk, Aug 10, 2017.

  1. Schmidtsk macrumors newbie


    Aug 10, 2017
    Have just ordered iMac 27" i7 4.2Ghz with AMD Radeon Pro 580 GPU for video editing using Avid.

    I would like to use a second display for my timeline and bins, and the Retina 5K for full screen playback. I like the idea of an Ultrawide like the LG34UM95 (3440 x 1440) which has thunderbolt. Has anyone tried this combo? USB3-C to Thunderbolt 2 converter would obviously be needed, but would it work? Would the GPU allow the two different resolutions simultaneously, or would the Retina display have to down-rez to HD?

    Thanks for any advice.
  2. Anonymous Freak macrumors 603

    Anonymous Freak

    Dec 12, 2002
    As long as you're not mirroring, it works fine. I use my MacBook Pro with a 4K display and two 1080p displays, and each works at its proper resolution perfectly. It's funny, as you drag a window quickly from a "HiDPI" (Retina) display to a "regular" display or vice versa, the window either appears oversized or tiny (depending on which direction you're dragging it,) for a few milliseconds before the OS realizes it has to resize it to or from HiDPI/Retina mode.

    And unless you have specific need for that second Thunderbolt 2 port the Thunderbolt version of that monitor provides, save the money and get the non-Thunderbolt version. Just use a USB-C-to-DisplayPort cable (or USB-C-to-HDMI.) If you have other Thunderbolt 2 devices, then sure, go ahead, it's probably worth it to leave your second Thunderbolt 3 port on the iMac itself available. But if you don't need that "outbound" Thunderbolt 2 port on the display, it's just extra money ($100 for the monitor plus the $50 for the adapter.)
  3. EugW macrumors 601


    Jun 18, 2017
    Here are my results with dual screen, with the adapters used.


    I don’t have the issue of window size mismatch for high vs vs low dpi when dragging windows over, not even for a few ms, maybe because the screens are the same physical size and one is a pixel quadrupled version of the other:

    5120x2880 and 2560x1440

Share This Page