Micron To Offer 2X GDDR5 Speed In 2016
 

I'm still fuzzy about the relationship between GDDR5X and GDDR6. A lot of reports seem to suggest that the latter is merely the former. With speeds from 10 to 14 Gb the next generation memory will be much faster and provide much needed bandwidth. Micron can easily call this memory GDDR6 as we have heard people from the graphics industry already using the term. The new memory will continue to use traditional component form factor, similar to GDDR5, reducing the burden and complexity of design and manufacturing.

http://www.hardocp.com/news/2015/12/...speed_in_2016/