Assassin Creed 4 - requirements
Operating System: Windows Vista SP2 or Windows 7 SP1 or Windows 8 (both 32/64bit versions)
Processor: Intel Core2Quad Q8400 @ 2.6 GHz or AMD Athlon II X4 620 @ 2.6 GHz.
RAM: 2 GB (4 GB recommended)
Video Card: Nvidia Geforce GTX 260 or AMD Radeon HD 4870 (512MB VRAM with shader Model 4.0 or higher)
That maybe pushing it so I would guess AC3 maybe a safer bet.