I've linked a second screen (1920x1080) to my iMac 27" (2560x1440) via HDMI (using a minidisplayport to HDMI adapter).
I want to mirror the first on the second but when I do this the first takes the resolution of the second which is lower. If instead I choose to extend the first on the second then the first keeps it resolution, but I can't access Mac OS X's interface from the second, only the windows I move to it.
The solution needs to work for 2 external screens.

2 Answers 2


In order to access Mac OS interface from another screen, go to System Preferences > Displays > Arrangement and take a look at the blue rectangles that represent the screens you currently have connected. One of them should have a white bar at the top, drag this bar to the screen that you want to access the OS interface from. That way you can keep the higher resolution, and access the interface. Unfortunately, if you mirror a display, it will take the lowest resolution because it cannot "create" the pixels required on the lower resolution screen in order to show a Mirrored display. If you want to keep the higher resolution, you have to extend the displays.

  • That sucks, I hope there's an alternative. What about Spaces ? I use Lion. Jul 24, 2013 at 22:44
  • It does suck, I've had to put up with it for years. Spaces just creates extra desktops that you can switch between, it doesn't have much to do with displays.
    – qaxf6auux
    Jul 25, 2013 at 20:18
  • Apparently with AirPlay you can choose which device's resolution will be used, so why can't it be done via cables. Jul 25, 2013 at 21:19
  • It sucks even more than I thought because every time I use the lower resolution screen it screws up my windows position and size on the high resolution screen. Isn't there a tool to save/load it ? Jul 26, 2013 at 19:12

There might not currently be (no existing software) a way to mirror a display and keep each displays' highest resolution but, since mirroring is used for displays that are in separate rooms (I assume, otherwise the other screen would serve as an extension) then it's possible to use some softwares that let you save all windows size and position and restores them automatically when a display is plugged/unplugged or mirror mode is activated/deactivated.

Stay ($15) does exclusively this.
Moom ($10) does this (with a slightly less evident setup) plus other windows positioning tricks.

N.B. some windows that are not real system windows could be impossible to save/restore, such as X11 and the Adobe Suite.

I found them at tool to remember window positions when I plug in/unplug an external display and https://stackoverflow.com/questions/533569/remember-window-sizes-and-placement-when-unplugging-and-replugging-second-monito

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .