For extra info, it looks like the CPU scaling only benefits up to 6 cores:
http://techreport.com/news/28026/amd-shows-off-directx-12-performance-with-new-3dmark-benchmark
Still a lot better than DX11's 2 core scaling, but an even cheaper FX-6300 or similar 6-core CPU may give just as much perfomance gain as an FX-8350/8-core.