AMD3D published Performance Analysis: Two Radeon RX 590 in Crossfire Mode
A quote from the article:
As we all know, AMD have disabled the ability run Crossfire (multi-GPU) configuration some time ago. Sadly, that decision was announced around the end of 2017. This means that all of their latest Radeon RX 5000-series graphics cards, which include RX 5500, 5600 and 5700 series (Navi), do not support Crossfire.Performance Analysis: Two Radeon RX 590 in Crossfire Mode
However, if you’re lucky enough to own AMD’s previous generation of graphics cards, such as the Radeon RX 570, RX 580 or a RX 590 (Polaris)… then you’ll be able to run 2 of these card in Crossfire mode (ideally matching models of course). Sadly, these RX 500 series will be the last graphics cards from AMD that can support Crossfire.