We will test every item before shipping to make sure all products are working well. Under normal use, the warranty is one year. If used in mining, the warranty is 3 months. There are three types of RX580 8GB. The appearance is different. But the chip is exactly the same. Three appearances are sent randomly. AMD Radeon RX580 chipset , It supports mining, mining hash rate in the range of 25-30MH/S.