Official specs from Steam

Far Cry 4 system requirements

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

Minimum

OSWindows 10 (64-bit)
Processor2.6 GHz Intel® Core™ i5-750 or 3.2 GHz AMD Phenom™ II X4 955
Memory4 GB RAM
GraphicsNVIDIA GeForce GTX 460 or AMD Radeon HD5850 (1 GB VRAM)
DirectXVersion 11
NetworkBroadband Internet connection
Storage30 GB available space
Sound CardDirectX-compatible (5.1 surround sound recommended)
Additional NotesWindows-compatible keyboard, mouse, optional controller (Xbox 360 Controller for Windows recommended)

Recommended

OSWindows 10 (64-bit)
Processor2.5 GHz Intel® Core™ i5-2400S or 4.0 GHz AMD FX-8350 or better
Memory8 GB RAM
GraphicsNVIDIA GeForce GTX 680 or AMD Radeon R9 290X or better (2 GB VRAM)
DirectXVersion 11
NetworkBroadband Internet connection
Storage30 GB available space
Sound CardDirectX-compatible (5.1 surround sound recommended)
Additional NotesSupported video cards at the time of release: NVIDIA GeForce GTX 460 or better, GeForce GTX 700 series; AMD Radeon HD5850 or better, Radeon R9 series. Note: Laptop versions of these cards may work but are NOT officially supported.

FAQ

What graphics card do I need for Far Cry 4?

Minimum: NVIDIA GeForce GTX 460 or AMD Radeon HD5850 (1 GB VRAM). Recommended: NVIDIA GeForce GTX 680 or AMD Radeon R9 290X or better (2 GB VRAM).

How much RAM does Far Cry 4 need?

Far Cry 4 needs 4 GB RAM at minimum, 8 GB RAM recommended.

How big is Far Cry 4?

Far Cry 4 requires 30 GB available space.

Does Far Cry 4 run on Mac or Steam Deck/Linux?

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