Virtual machines require a certain amount of available overhead memory to power on. You should be aware of the amount of this overhead.

The following table lists the amount of overhead memory a virtual machine requires to power on. After a virtual machine is running, the amount of overhead memory it uses might differ from the amount listed in the table. The sample values were collected with VMX swap enabled and hardware MMU enabled for the virtual machine. (VMX swap is enabled by default.)

Note: The table provides a sample of overhead memory values and does not attempt to provide information about all possible configurations. You can configure a virtual machine to have up to 64 virtual CPUs, depending on the number of licensed CPUs on the host and the number of CPUs that the guest operating system supports.
Table 1. Sample Overhead Memory on Virtual Machines
Memory (MB) 1 VCPU 2 VCPUs 4 VCPUs 8 VCPUs
256 20.29 24.28 32.23 48.16
1024 25.90 29.91 37.86 53.82
4096 48.64 52.72 60.67 76.78
16384 139.62 143.98 151.93 168.60