Itanican
Level 1 (4 points)
Notebooks

Q: Bootcamp with Thunderbolt

Since the 10.11.6 El Capitan update, I can no longer boot my 2013 Macbook Air into Windows 10 with the Thunderbolt screen active. Before the update, if I watched the Thunderbolt screen carefully I could tell when it went from dead black to slightly less black - then quickly holding the Option key I could bring up the boot menu and choose Windows.

 

Since the update, the Thunderbolt screen does not activate until well into the Mac boot process, way too late to switch to Windows.

 

Why did you remove this critical functionality Apple?

MacBook Air, OS X El Capitan (10.11.6), Thunderbolt

Posted on Aug 6, 2016 3:36 AM

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Itanican

Q: Bootcamp with Thunderbolt

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  • Helpful answers

  • by Patcell,

    Patcell Patcell Aug 6, 2016 10:20 AM in response to Itanican
    Level 1 (41 points)
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    Aug 6, 2016 10:20 AM in response to Itanican

    As far as I understand, you have an external display connected to the Thunderbolt port on your Mac, correct?

     

    There is no particular time that you need to hit the 'option' key in order to get to the boot selection screen.  As soon as you click restart, press and hold the 'option' key and you will be presented with the boot selection once OS X has shut down. 

  • by Itanican,

    Itanican Itanican Aug 7, 2016 8:38 AM in response to Patcell
    Level 1 (4 points)
    Notebooks
    Aug 7, 2016 8:38 AM in response to Patcell

    Yes, the  Thunderbolt monitor is connected to the Mac.

     

    Holding down the Option key will present the boot selection screen on the Macs screen only, not the Thunderbolt display.

     

    Before the update, waiting for the Thunderbolt to activate before holding the Option key was the only way to see the boot selection screen on the Thunderbolt. Now the Thunderbolt display only activates after its too late to see the boot selection screen.

  • by Patcell,

    Patcell Patcell Aug 7, 2016 9:11 AM in response to Itanican
    Level 1 (41 points)
    Notebooks
    Aug 7, 2016 9:11 AM in response to Itanican

    Okay, I see what you're saying...  If you select to boot to Windows from the built-in display, does the Thunderbolt display activate once Windows has booted?

  • by Itanican,

    Itanican Itanican Aug 7, 2016 11:25 AM in response to Patcell
    Level 1 (4 points)
    Notebooks
    Aug 7, 2016 11:25 AM in response to Patcell

    You mean select boot to Windows from Mac? No, if the Thunderbolt isn't active by the time the Windows 10 logo comes up its too late.

  • by Loner T,

    Loner T Loner T Aug 7, 2016 11:57 AM in response to Itanican
    Level 7 (23,633 points)
    Safari
    Aug 7, 2016 11:57 AM in response to Itanican

    Itanican wrote:

     

    Since the 10.11.6 El Capitan update, I can no longer boot my 2013 Macbook Air into Windows 10 with the Thunderbolt screen active. Before the update, if I watched the Thunderbolt screen carefully I could tell when it went from dead black to slightly less black - then quickly holding the Option key I could bring up the boot menu and choose Windows.

    To confirm, is your Mac in Clamshell mode?

     

    Since the update, the Thunderbolt screen does not activate until well into the Mac boot process, way too late to switch to Windows.

    This is related to EFI firmware on your Mac, not OS X versions. OS X is not in the picture when the Boot manager comes up. If you really want to test this, install Mavericks on an external disk, and boot from it and check. Also check Software Update for any applied EFI updates. Also, see About EFI and SMC firmware updates for Intel-based Mac computers - Apple Support .

     

     

    Why did you remove this critical functionality Apple?

    This seems to be an optimization to reduce power consumption. The TB display consumes 250W at maximum power.

    Apple Thunderbolt Display - Technical Specifications

  • by Itanican,

    Itanican Itanican Aug 7, 2016 3:05 PM in response to Loner T
    Level 1 (4 points)
    Notebooks
    Aug 7, 2016 3:05 PM in response to Loner T

    Thanks for the links. Yes, the lid is closed during boot-up, I'm holding Option on the wired USB Apple keyboard. This contributes to the problem as well, because the keyboard sometimes takes a very long time to activate or get power - pressing caps-lock, the green light does not illuminate. No chance for the Mac to detect the Option key being held if it boots before the keyboard is activated.

  • by Loner T,

    Loner T Loner T Aug 7, 2016 5:26 PM in response to Itanican
    Level 7 (23,633 points)
    Safari
    Aug 7, 2016 5:26 PM in response to Itanican

    Please connect the USB Keyboard to the USB port on the Mac, not the TB monitor, and test. If you use a USB Mouse as well, connect both the Keyboard and Mouse to the Mac, not the TB monitor.

  • by Itanican,

    Itanican Itanican Aug 7, 2016 7:06 PM in response to Loner T
    Level 1 (4 points)
    Notebooks
    Aug 7, 2016 7:06 PM in response to Loner T

    The keyboard is not connected to the TB monitor, its connected to the Mac. The mouse is connected to the keyboard.

  • by Loner T,

    Loner T Loner T Aug 7, 2016 7:18 PM in response to Itanican
    Level 7 (23,633 points)
    Safari
    Aug 7, 2016 7:18 PM in response to Itanican

    The Keyboard is acting as a USB hub in your current configuration. As a test, disconnect the USB mouse, leaving only the Keyboard connected to the Mac. You can use the arrow keys on the keyboard to navigate the Boot devices. Try using Alt/Option key in this configuration.

     

    On a 2012 13-in MBP, with two USB ports, one each for Keyboard and Mouse, I can use the Alt/Option key in Clamshell mode with the display connected to an Apple TB monitor, and choose Windows, Recovery HD or OSX.

     

    From MacBook Air (13-inch, Mid 2013) - Technical Specifications and MacBook Air (11-inch, Mid 2013) - Technical Specifications there are two USB3 ports on either MBA model, so one each can be used for Keyboard and Mouse respectively. Other USB devices/hubs can be connected to the TB monitor's USB ports.