Expreview based in Asia noticed that a new SKU based on the Radeon RX 590 is released in their region, it would be called a GME edition.

Clock frequencies for the base clock are yet to be disclosed, but the GME version would have roughly an up-to 120 MHz clock overall lower clock compared to regular editions. Clocks vary a little per brand though. So basically that means you're back at Radeon RX 580 performance levels again.

Example: The core frequency of XFX RX 590GME Black Wolf Edition 8G is 1460MHz, which is 120MHz lower than the original RX 590 Black Wolf Edition. The GME editions are brand divers as entires for XFDX, ASRock, PowerColor, and Sapphire have already been spotted. Weird right?

Updated March 9th:

The very same website has gotten their hands on a sample, it's really an RX 580 based on 14nm, whereas the normal 590 is based on a 12LPP (12nm) GPU.  

The Expreview review is based on an XFX-branded RX 590 GME, and it is fitted with a Polaris 20 XT GPU. That is the older 14nm baked product. The GPU clock speeds are close to a reference clocked RX 590 though, 1460 MHz base (1469 MHz is reference RX 590). Performance-wise the product sits in between the 580 and 590. The RX 590 GME right now is only available in Asia, the good news is that it is priced lower than RX 590 cards (just over 5%)

Source: Expreview

Radeon RX 580 chip powers the new RX 590 GME (updated)