R7 250. Get a DDR 5 version. http://www.techspot.com/review/781-amd-a10-7850k-graphics-performance/page5.html
Give you and idea of what to expect. Basically some games do better some actually worse in dual graphics.
Honest I say forget the dual graphics and get a good card. Those charts don't impress me enough to think its worth it. A nvidia 950 would crush any dual graphics.