Crysis 3 system requirements for PC hardware will be similar if not the same as Crysis 2, because both games are powered by the CryEngine 3 game engine. Crysis 3 system requirements will still be quite demanding though, as this has been the case with Crysis games since the very beginning. Here are the full PC specs require of the game:
The hunted becomes the hunter in the CryEngine-powered open-world shooter Crysis 3! Players take on the role of 'Prophet' as he returns to New York in the year in 2047, only to discover that the city has been encased in a Nanodome created by the corrupt Cell Corporation. The New York City Liberty Dome is a veritable urban rainforest teeming with overgrown trees, dense swamplands and raging rivers. Within the Liberty Dome, seven distinct and treacherous environments become known as the Seven Wonders. This dangerous new world demands advanced weapons and tactics. Prophet will utilize a lethal composite bow, an enhanced Nanosuit and devastating alien tech to become the deadliest hunter on the planet.
Prophet is on a revenge mission after uncovering the truth behind Cell Corporation's motives for building the quarantined Nanodomes. The citizens were told that the giant citywide structures were resurrected to protect the population and to cleanse these metropolises of the remnants of Ceph forces. In reality, the Nanodomes are CELL's covert attempt at a land and technology grab in their quest for global domination. With Alien Ceph lurking around every corner and human enemies on the attack, nobody is safe in the path of vengeance. Everyone is a target in Prophet's quest for retribution. 
Crysis 3 system requirements (minimum)
    CPU: 2.8 GHz dual core processor, Intel Core 2 Duo or AMD Phenom X2 or better
    RAM: 2GB
    Graphics: DirectX 10 graphics card with 1 GB RAM, Nvidia 400-series or AMD Radeon 5000-series.
    Operating system: Windows Vista
    DirectX 9c sound card
    16 GB free hard drive space

Crysis 3 system requirements (recommended)
    CPU: 2.4 GHz quad core processor, Intel Core i5 or better
    RAM: 2GB (4 GB for 64-bit operating systems)
    Graphics: DirectX 11 compatible video card with 1GB RAM, Nvidia GTX 500-series or AMD 6000-series or better.
    Operating system: Windows 7, Win 7 64-bit is preferred
    DirectX 9c sound card, dedicated audio card is preferred
    16 GB free hard drive space