Here are the Assassin’s Creed Unity System Requirements (Minimum)
CPU: Intel Core i5-2500K @ 3.3 GHz or AMD Phenom II x4 940 @ 3.0 GHz or AMD FX-8350 @ 4.0 GHz
CPU SPEED: Info
RAM: 6 GB
VIDEO CARD: NVIDIA GeForce GTX 680 or AMD Radeon HD 7970 (2 GB VRAM)
DEDICATED VIDEO RAM: 2 GB
PIXEL SHADER: 5.0
VERTEX SHADER: 5.0
OS: Windows 7 SP1, Windows 8/8.1 (64-bit operating system required)
FREE DISK SPACE: 50 GB
SOUND CARD: Yes

Assassin’s Creed Unity Recommended Requirements
CPU: Intel Core i7-3770 @ 3.4 GHz or AMD FX-8350 @ 4.0 GHz or better
CPU SPEED: Info
RAM: 8 GB
VIDEO CARD: NVIDIA GeForce GTX 780 or AMD Radeon R9 290X (3 GB VRAM)
DEDICATED VIDEO RAM: 3 GB
PIXEL SHADER: 5.0
VERTEX SHADER: 5.0
OS: Windows 7 SP1, Windows 8/8.1 (64-bit operating system required)
FREE DISK SPACE: 50 GB
SOUND CARD: Yes