Cheapest AMD CPU that won't bottleneck a r9 380?

Poixon

Commendable
Feb 24, 2016
24
0
1,520
Later this month I was considering upgrading to an r9 380, however I soon realised that my CPU will drastically bottleneck it. Some are saying that the Althlon X4 860K Black Edition will be fine with some OC'ing, others are saying it will still bottleneck. Could anyone tell me a good CPU that won't botteneck?

SPECS

CPU- AMD a6 6400k black edition
Motherboard- ASUS a88xm-plus
RAM- Corsair Vengeance Pro 8GB (2x4GB) DDR3 2400MHz C11 Memory Kit
CPU cooler- Arctic Alpine 64 GT Socket AMD Processor Cooler
Video Card -XFX R7 360 DD 2GB GDDR5
Power Supply Corsair VS Series 450 Watt Power Supply (obviously upgrading to 550w)
Hard drive(s) 1x 500gb OS hdd, 1x 1tb files hdd
Operating System- Windows 10 pro