8GB vs 16GB RAM for running a 4GB VM on Windows or macOS: 16GB is the minimum for comfortable use

With 8GB total, the host OS eats 2–4GB before you add apps, leaving maybe 4GB for the host while the VM takes 4GB—both fight over RAM, causing swapping and lag. 16GB changes the math: host uses 8–10GB easily, VM gets its 4GB, and you have a buffer with no swapping. Linux hosts might squeeze by on 8GB with tuning, but on Windows or macOS, 16GB is where VM use stops being painful.