You should move your question to the right place, the graphics forum would be best, as kingfish suggested.
Did you recently change drivers and this started after that change? If so a you might want to regress to the previous driver.
If not set your Power Limit to +50 in Wattman in Radeon Settings see if that helps. I've seen 580's have stability issues when hitting about 77 degrees even though this is supposed to be okay for those cards. Regardless I have had 2 of them myself exhibit this behavior. I have however never had one display a picture like what you posted. You can set a manual fan curve in Wattman that will run the fan at max sooner and see if that helps too.
I would also send those pics and ask your question to the support department at Sapphire that made your card. If a simple software tweak doesn't help it may be time to do an RMA. Anyway they should be able to walk you through trouble shooting steps and in general they do make the best AMD cards. Cards mostly crap out in the first 90 days or they last for years.
