Not a whole lot of details, but it seems the Radeon RX 590 card is based on a new 12nm-based refresh of AMD's Polaris GPU. Recent rumors indicate AMD is planning to launch third-generation Polaris chips sometime in November.
These cards are expected to feature higher clockspeeds, and may offer up to 15 percent higher performance than current parts. The product code of this ROG STRIX Gaming card reveals it has 8GB GDDR5 memory, the same as its predecessors.