Official specs from Steam

Metal Gear Solid V: The Phantom Pain system requirements

Minimum and recommended PC specs as listed by the developer on Steam.

Minimum

OSWindows 7x64, Windows 8x64, Windows 10x64 (64-bit OS Required)
ProcessorIntel Core i5-4460 (3.40 GHz) or better; Quad-core or better
Memory4 GB RAM
GraphicsNVIDIA GeForce GTX 650 (2GB) or better (DirectX 11 card Required)
DirectXVersion 11
Storage28 GB available space
Sound CardDirectX 9.0c compatible sound card

Recommended

OSWindows 7x64, Windows 8x64, Windows 10x64 (64-bit OS Required)
ProcessorIntel Core i7-4790 (3.60GHz) or better; Quad-core or better
Memory8 GB RAM
GraphicsNVIDIA GeForce GTX 760 (DirectX 11 graphic card required)
DirectXVersion 11
Storage28 GB available space
Sound CardDirectX 9.0c compatible sound card (Surround Sound 5.1)

FAQ

What graphics card do I need for Metal Gear Solid V: The Phantom Pain?

Minimum: NVIDIA GeForce GTX 650 (2GB) or better (DirectX 11 card Required). Recommended: NVIDIA GeForce GTX 760 (DirectX 11 graphic card required).

How much RAM does Metal Gear Solid V: The Phantom Pain need?

Metal Gear Solid V: The Phantom Pain needs 4 GB RAM at minimum, 8 GB RAM recommended.

How big is Metal Gear Solid V: The Phantom Pain?

Metal Gear Solid V: The Phantom Pain requires 28 GB available space.

Does Metal Gear Solid V: The Phantom Pain run on Mac or Steam Deck/Linux?

There is no native macOS version. There is no native Linux build (Proton compatibility may vary).