Look at the specs for upcoming game like Assassin's Creed Unity
Minimum PC Specs:
Intel Core i5-2500K @ 3.3 GHz or AMD FX-8350 @ 4.0 GHz or AMD Phenom II x4 940 @ 3.0 GHz processor
6 GB RAM
NVIDIA GeForce GTX 680 or AMD Radeon HD 7970 (2 GB VRAM) video card
Recommended PC Specs:
Intel Core i7-3770 @ 3.4 GHz or AMD FX-8350 @ 4.0 GHz or better processor
8 GB RAM
NVIDIA GeForce GTX 780 or AMD Radeon R9 290X (3 GB VRAM) video card
Additionally, the following requirements must be met:
Windows 7 SP1 or Windows 8/8.1 (64-bit versions only)
DirectX Version 11
DirectX 9.0c compatible sound card with latest drivers
50 GB available HDD space
I'd say we can expect the witcher 3 to require at least those and maybe even higher cpu and gpu to run with ultra settings.
Minimum PC Specs:
Intel Core i5-2500K @ 3.3 GHz or AMD FX-8350 @ 4.0 GHz or AMD Phenom II x4 940 @ 3.0 GHz processor
6 GB RAM
NVIDIA GeForce GTX 680 or AMD Radeon HD 7970 (2 GB VRAM) video card
Recommended PC Specs:
Intel Core i7-3770 @ 3.4 GHz or AMD FX-8350 @ 4.0 GHz or better processor
8 GB RAM
NVIDIA GeForce GTX 780 or AMD Radeon R9 290X (3 GB VRAM) video card
Additionally, the following requirements must be met:
Windows 7 SP1 or Windows 8/8.1 (64-bit versions only)
DirectX Version 11
DirectX 9.0c compatible sound card with latest drivers
50 GB available HDD space
I'd say we can expect the witcher 3 to require at least those and maybe even higher cpu and gpu to run with ultra settings.