Why would you want to run this powerful card on Windows 8 ?
The last driver is from 2015.
If you stick to the officially supported OS's. you can use the latest driver.
Due to I don't like Windows 10 and because some old software (32-bits) runs perfectly in Windows 8 x86.
Even with Windows 8.1 x86/x64 W5100 remains without be recognized even installing the drivers downloaded from the AMD website
It is something strange that Windows 7 x86/x64 recognized the graphic card.