There's a lot of threads that have a wish list or a guess at what AMD card the new iMacs will get, the best guess being a AMD 460 which does not perform nearly as well as nVidia for good reasons. For that matter, the 395x might be the better option. But this is all cause by speculation. Here's what I have found: Starting with this article by our own: http://www.macrumors.com/2016/04/19/amd-polaris-2016-macs/ According to this, the Polaris 11 has a power range designed for notebooks. The Polaris 10 is designed for the iMac or greater. So what is the difference between the 10 and 11? http://www.notebookcheck.net/uploads/tx_nbc2/AMD_Polaris_10_and_Polaris_11.jpg This gives us only TFLOPS to compare by...not a very good indicator, but enough to give us a good starting point. The iMac should be on order of at least 5 TFLOPS. Finally: http://www.pcadvisor.co.uk/feature/...rce-gtx-1080-vs-gtx-1070-vs-gtx-1060-3640925/ This indicates we are looking somewhere between the 1060 and 1070 in performance. The RX 470 is first to meet the specs...it is a polaris 10. As nothing has been mentioned with a RX 490, I wouldn't hold my breath on that and would expect to see a performance between the nVidia 1060 and 1070. http://wccftech.com/amd-radeon-rx-480-polaris-10-graphics-card-leak/ http://wccftech.com/amd-rx-470-460-specs-performance-launch-dates/ The best of the benchmarks I can currently find: http://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html From the 395x, we should still see a considerable performance boost looking at the 1060...I just don't know how much over the 1060. Feel free to chime in thoughts. Update: AMD Has designated the 490 as built on Vega and won't come any sooner than this spring. That leaves us with the 470-480 and one X build which will either be 480x or 485x, if AMD designates any 485. Regardless, we should see a performance increase on each model and a possibility of a power/temperature drop.