Overclocking
Intel's driver has a bug reporting the wrong shader count, the correct count is 2304, not 1920. Performance is in line with 2304.
Intel's control panel offers a good range of overclocking options—no third party software required. Unlike the first generation, Alchemist, memory overclocking is fully supported on Battlemage now, and you can also tweak the voltage-frequency curve.
While our B580 reviews in December were plagued by issues with the OC features in the control panel, things worked a bit better with the newer driver. On crash, there would be a popup in the driver settings "System crashed, do you want to apply or reset the previous overclock."
The gains are still not as big as I would have expected, but they aren't that bad, actually. 9.95% real-life performance gained overall.