CPU is fine. But the AC games are known for running poorly and it has nothing to do with being "next gen" looking. They look good but far from amazing. They haven't changed much since previous gen.
GPU like others have said is too old (~2008). A card around 2k should be fine. Maybe 2GB more ram, makes a big difference in modern games. The PSU will probably also need an upgrade.
After that, worst case scenario is AC Unity will be running at at least 30fps on medium/high, which is on par with if not better than PS4 (1600x900 @30fps with fps dips).
GPU like others have said is too old (~2008). A card around 2k should be fine. Maybe 2GB more ram, makes a big difference in modern games. The PSU will probably also need an upgrade.
After that, worst case scenario is AC Unity will be running at at least 30fps on medium/high, which is on par with if not better than PS4 (1600x900 @30fps with fps dips).