This is the industry favorite. The trick is to install Unity normally once onto the external drive, then hijack the internal cache folders (which usually live in %APPDATA% and %LOCALAPPDATA%) to point back to the drive.
What you need:
Step-by-Step:
Install Unity Editors to the external drive:
Redirect Unity’s Global Cache (The Magic Step): unity portable install top
Redirect the Unity Hub Cache:
Result: When you plug the drive into any Windows PC (as drive U:), Unity will think these caches are on the system drive, but they are physically on your SSD. Speed is preserved, and you don't fill up the host PC's storage. This is the industry favorite
The Unity Editor is a complex software ecosystem comprising the core C++ engine, managed .NET assemblies, and a rapidly iterating versioning system. The default deployment mechanism utilizes the Unity Hub, a centralized management tool designed to streamline installation, licensing, and project association. However, the standard installation path (typically C:\Program Files\Unity\Hub\Editor on Windows or /Applications/Unity/Hub/Editor on macOS) entrenches the software within the system architecture.
For power users, educators, and DevOps engineers, the need for a "portable" installation—often colloquially referred to or searched for as a "portable install top" (implying a top-tier or optimized portable setup)—is driven by the requirement for mobility, version isolation, and system cleanliness. This paper outlines the technical strategies for achieving a truly portable Unity environment, distinct from the constraints of the standard Hub integration. Step-by-Step:
Let’s assemble a real-world walkthrough using Method #1.
U:\Unity\Hub.U:\Unity\Editors.U:\Unity\Projects\MyGame.%LOCALAPPDATA%\Unity to U:\Unity\Cache.U:\Unity\Hub\UnityHub.exe. Your Editor and Project are right there.