Set How Much Memory is Allocated to Windows

Parallels Desktop is set to allocate a certain amount of your Mac's available RAM memory to Windows and the rest to macOS. If too much memory is allocated to Windows, macOS may slow down, which in turn can cause Windows programs to slow down because they're running on top of macOS. If, on the other hand, too much memory is allocated to macOS, then macOS applications may run well but Windows programs might slow down.

To optimize the performance of both Windows and macOS, set the memory allocated to Windows to be somewhere within the recommended range.

To set how much memory is allocated to Windows:

1. Shut down Windows.
2. Choose Actions > Configure > Hardware > CPU & Memory.
3. Move the memory slider to somewhere within the recommended range, indicated by the graphic under the slider.

   If you use Windows programs that require lots of memory, like 3D or video production programs, it's best to set the memory allocation towards the high end of the range (move the slider to the right). If not, it's usually best to set it closer to the middle.

   Note: No matter how much memory (RAM) your Mac has, the maximum amount of memory that can be assigned to Windows is 8 GB.

If you change this setting and then you don't like how Windows is performing, then try a different setting.