Strangely, we've received a 2 back to back customers asking about windows 8 Drivers for their Rx 580s. If they choose to not upgrade to win 10, or downgrade to 7, what are their options? Historically, we've asked they try the windows 7 drivers and those worked during the transition from windows 7 to 8, but i cant confirm they work for the 500 series yet.
Mark at XFX
Unfortunately Windows 8 is not supported on RX400/RX500 and higher products.
Windows 7 drivers may work, but that's probably not the best option.