Just wondering if this is relevant to the latest Win10 1803 update. If so, you'll need to downgrade that ver of windows to an earlier update. This may mean performing a clean slate install of win10 via the media creation tool.
Unfortunately since you have not given enough of the requested information (see links in the forum headers) to be able to post and for anyone to be able to help properly it is hard to say. Please follow this when posting: Read This First
No as I myself have an RX 580 and know that it works fine with the latest Windows 10 64 bit 1803 and was fine with 1709 before that as well. You likely are suffering from the most common issue and this is not a default setting. Mine will also suffer from the issues you describe if you don't change these settings. First make sure your Windows power profile is set to high performance not balanced. Next go to Radeon Settings/Gaming/Global Settings/Global Wattman and find the "Power Limit" slider and slide it to its maximum, all the way to the right. Likely this will be +50. This usually will take care of the issues you have. If it does not I suggest running DDU from safe mode then reinstalling the latest driver again and setting the power limit slider back to its max. You will have to set this back to its max after every driver upgrade or if the driver crashes as it returns settings to default. Good Luck!