TerraForm is a plugin for Unreal Engine Editor and as such, system requirements are the same as those for UE4.
As Epic says:
“For developing with UE4, we recommend:
- Desktop PC with Windows 7 64-bit or later
- Quad-Core Intel/AMD processor or better
- 8GB+ RAM
- 2GB+ VRAM
- DX11 compatible video card.
UE4 will run on desktops and laptops below these recommendations, but performance may be limited.”
In addition to this, you’ll need an Internet connection to activate TerraForm and validate your subscription.