The performance delivered by the XFX RX 590 Fatboy shows that the higher clock speeds deliver around a 10% bump in performance over a highly clocked RX 580, with that result improving as you cycle the clock speeds down to the reference clock speeds. Overclocking delivered nice performance gains without adding onto the power consumption. Pretty amazing when I was able to push the card up to another 100MHz on the core and 250MHz on the Micron GDDR5 memory. The overclocking margins would not be considered high by any standard, but when you compare it to the 14nm parts you can see upwards of 300MHz of core clock speed or more by comparison. That is impressive.