Ubisoft have revealed the minimum PC Requirements for Watch Dogs and they’re probably higher than any other game out there at the moment.
Minimum
Supported OS: Windows Vista SP2 64bit, Windows 7 SP1 64bit, Windows 8 64bit
Processor: Intel Core 2 Quad Q8400 @ 2.66Ghz or AMD Phenom II X4 940 @ 3.0Ghz
RAM: 6 GB
Video Card: 1024 VRAM DirectX 11 with Shader Model 5.0 (see supported list)
Sound Card: DirectX 9 compatible Sound Card
This product supports 64-bit operating systems ONLY
Recommended:
Processor: Core i7 3770 @ 3.5Ghz or AMD FX-8350 @ 4.0Ghz
RAM: 8 GB
Video Card: 2048 VRAM DirectX 11 with Shader Model 5.0 or higher (see supported list)
Sound Card: Surround Sound 5.1 capable sound card
Supported Graphics Cards:
nVidia GeForce GTX460 or better, GT500, GT600, GT700 series;
AMD Radeon HD5850 or better, HD6000, HD7000, R7 and R9 series
Intel® Iris™ Pro HD 5200
We’ll have more on Watch Dogs closer to release.