Here is good review of RX 590, but nothing about hashrate:
https://hexus.net/tech/reviews/graphics/124211-amd-radeon-rx-590/According to review:
"Though no obvious changes in architecture have occurred since the original Polaris XT (Radeon RX 480)
launch in June 2016, this latest GPU, Radeon RX 590, kicks up the core clock by over 20 percent.
Radeon RX 590, therefore, is an overclocked Radeon RX 580 which is an overclocked Radeon RX 480."
I think there's something afoul about that article. How can you go from a 14nm chip to a 12nm chip and double the power requirements? 225 watts? Don't smaller die chips usually go the other way on power consumption? If you're not making a more power efficient and higher performance product what's the point? Everyone will simply switch back to $100 used RX 470s and 480s and call it a day while AMD goes down in flames. Something is definitely odd.
Chris B.