I have tested the RX480 in a 7850K APU at stock settings. In alot of games I get similar performance to my I5 4560, but with higher cpu utilization. About 50% average with spikes upto 80%. In a few CPU intensive areas, like in Tombraider with alot of stuff falling down, I have gotten dropped frame rates due to CPU can't keep up. but in most cases, its fine. Overclocked 860K should be much stronger than the 7850, so I imagine an RX460 and an RX470 should work just fine in this. Consider though that if you ever upgrade, you will need to change entire MB, RAM, and CPU, as next upgrade path for AMD is Zen, with AM3, and DDR4. so buying this now is not good idea unless you plan to upgrade everything.