As a foreword, here are the software requirements for running the Godot 3.0 editor:
- Windows 7 or newer, macOS 10.10 or newer, Linux (64-bit or 32-bit x86)
- Hardware supporting OpenGL 3.3 Core Profile
Here are GPUs supporting OpenGL 3.3:
- AMD Radeon HD 7000 series GPU or newer1
- NVIDIA GeForce 8 series GPU or newer2
- Intel 3rd generation (Ivy Bridge) series GPU or newer
1: Some people have reported Radeon HD 6000 series GPUs to work as well.
2: Some users have reported issues with GeForce 8 and 9 series GPUs; GeForce 400 (Fermi) GPUs and newer should always work, though.
As for hardware recommendations, remember that the Godot 3 renderer is fairly high-end-oriented. However, it is difficult for Godot developers to publish "universal" hardware requirements since different kinds of games are going to widely differ in terms of hardware requirements.
Any remotely modern CPU will run Godot fine; 2 cores should be enough to keep the editor running smoothly. However, if you plan on writing C++ modules or using GDNative, it's a better idea to get a quad-core CPU (or more) to help cut the compile times down.
Godot is relatively light on RAM – the editor can operate just fine with 4 GB of RAM. It's a good idea to get at least 8 GB if possible, especially if developing 3D games or when planning to run other programs in the background.
It's probably the most important part of a game development workstation. If you're going to develop 2D games, you won't need a fast GPU – integrated graphics will do fine in most cases. In contrast, if you want to develop 3D games, you will most likely need a dedicated graphics card. It doesn't always need to be very fast; even something like a GeForce GTX 1050 (which currently costs $130 in new condition) will be enough for 3D game development, provided you do not push the settings all the way up.
The Godot editor is very frugal in terms of storage space, compared to other engines such as Unity or Unreal Engine 4. As of Godot 3.0, the editor binary itself is around 35 MB uncompressed, a size which varies slightly depending on the compiler and optimizations used; export templates are 420 MB once uncompressed. Configuration and cache files weigh less than 3 MB in total, which means that a "complete" Godot editor installation will occupy less than 500 MB on disk, excluding project files.