Benchmarks compiled and aggregated by tipster @_rogame indicate that AMD's new Smart Access Cache technology might not offer a game-changing performance uplift in most cases. Nevertheless, the same benchmarks indicate that Big Navi's raw raster performance could make that a moot point.
https://www.notebookcheck.net/AMD-s-Smart-Access-Cache-might-not-deliver-massive-performance-gains-but-Big-Navi-s-raw-raster-performance-could-compensate.501064.0.html
...That's pretty insane, I think this beat most people's expectations of Big Navi.
"Smart Access Cache" is not the name of any feature. It is "Smart Access Memory" which allows direct CPU to GPU memory access. "Cache" is not the correct term. Odd article to use a made up feature name so many times.