How many RAM can be use after assign to Parallel

Hello,
When you allocate 4GB of RAM, it's important to understand that this memory is allocated to the virtual machine and not directly used by Parallels Desktop itself. Parallels Desktop is a virtualization software that allows you to run other operating systems, like Windows, alongside macOS.

When the virtual machine is not running, whether it's suspended or completely shut down, the allocated virtual RAM is essentially offloaded back to the macOS system. This means that your macOS will have access to the full 16GB of RAM when the virtual machine is inactive.

Also, please note that we strongly recommend keeping the value within the recommended range. Assigning more RAM than recommended may cause severe performance degradation of both Mac and the virtual machine. This is why we advise using the Automatic Resource Manager feature as it allows Parallels Desktop to evaluate your Mac hardware before starting a virtual machine to allocate as many resources as needed to provide a better out-of-the-box experience.

The topic of RAM Management is covered in our knowledge base article: https://kb.parallels.com/113649 in detail.

Thank you.