Minimum and recommended PC specs for Horizon Zero Dawn have been posted. Here’s what you will need to run the game on PC: Minimum Requirements

Requires a 64-bit processor and operating system OS: Windows 10 64-bits Processor: Intel Core i5-2500K@3.3GHz or AMD FX 6300@3.5GHz Memory: 8 GB RAM Graphics: Nvidia GeForce GTX 780 (3 GB) or AMD Radeon R9 290 (4GB) DirectX: Version 12 Storage: 100 GB available space

Recommended 

Requires a 64-bit processor and operating system OS: Windows 10 64-bits Processor: Intel Core i7-4770K@3.5GHz or Ryzen 5 1500X@3.5GHz Memory: 16 GB RAM Graphics: Nvidia GeForce GTX 1060 (6 GB) or AMD Radeon RX 580 (8GB) DirectX: Version 12 Storage: 100 GB available space

When released, you can expect the game to support ultra-wide resolutions, an unlocked framerate, controller options, a benchmarking tool, and graphical customization options and up to 120fps.
The package includes the base game as well as The Frozen Wilds expansion. It also comes with the Carja Storm Ranger Outfit and Carja Mighty Bow, Carja Trader Pack, Banuk Trailblazer Outfit, and Banuk Culling Bow, Banuk Traveller Pack, Nora Keeper Pack, and a digital artbook. It will set you back $50. Horizon Zero Dawn arrives on PC August 7.