http://www.pcgamer.com/fallout-4-system-requirements-released/
Minimum
Windows 7/8/10 (64-bit OS required)
Intel Core i5-2300 2.8 GHz/AMD Phenom II X4 945 3.0 GHz or equivalent
8 GB RAM
30 GB free HDD space
NVIDIA GTX 550 Ti 2GB/AMD Radeon HD 7870 2GB or equivalent
Recommended
Windows 7/8/10 (64-bit OS required)
Intel Core i7 4790 3.6 GHz/AMD FX-9590 4.7 GHz or equivalent
8 GB RAM
30 GB free HDD space
NVIDIA GTX 780 3GB/AMD Radeon R9 290X 4GB or equivalent
I think you should be able to play fallout 4 just fine. I would recommend medium settings. I am running two 270's myself and I can run the game on ultra (with some lag) with my amd fx 4170.