There seems to be some sort of a bug with VirtualBox's Retina display support, too, because when switching to Seamless mode the Windows desktop takes up roughly 65% of the screen, leaving the rest for macOS apps. In our tests we didn't find VirtualBox to be lagging behind any of the paid virtual machine software packages.
The default screen resolution for Mac OS X VirtualBox Guest is 1024×768.
Below shows how to change the screen resolution of Mac OS VirtualBox guest running on Windows 10.
VirtualBox allows you to install NT and Server 2003 versions as well as older versions such as Windows 3.x or even IBM OS / 2 on the 2018 computers of the last generation. Apple users have the same pleasure to use VirtualBox on their machines and the ability to host a Mac VM client session is a plus for any developer there. The first option is to enable the HiDPI support under VirtualBox Settings Display, check “ Use Unscaled HiDPI Output ” and leave the Scale Factor 100%. This will result in Windows to startup with a screen resolution of 2880×1800 pixel on a 13-inch MacBook Pro.
VirtualBox for Mac OS X is an extremely popular virtualization application with an amazingly rich functionality. The tool is absolutely cross-platform and is available for Windows, Linux, Solaris and Mac OS systems. It can run everywhere from small embedded systems or desktop class machines to Cloud solutions. The tool has been popular for more. Host is OS X 10.8.2 on a MacBook Pro with Retina display. When Aero is activated, the Windows 7 display suddenly gets pushed up by about 25 pixels. It's like instead of drawing the Win 7 video driver output in the content area of the window, VirtualBox starts drawing it.
Steps
1. Open “Command Prompt”. (press Win + x and select “Command Prompt”)
2. Navigate to VirtualBox folder in which “VBoxManage.exe” resides.
e.g.)
3. Set resolution by typing the command below.
The third parameter (i.e. “High Sierra”) should be your VM name.
Virtualbox Mac Retina
4. Start the VM
Virtualbox For Mac Retina Software
References
[1] Fix VirtualBox macOS High Sierra Screen Resolution (1920×1080 – 4K – 5K)