16GB vs 32GB+ RAM for multiple VMs: 32GB is the realistic minimum for running several VMs simultaneously.

16GB maxes out fast when running multiple VMs—each needs 2–4 GB just to boot, plus the host OS. Once RAM fills up, swapping to disk kills performance and can freeze or crash guests. For a test lab or dev environment with a few VMs, 32GB is the realistic minimum; go 64GB for heavy Windows Server or Linux desktops.