Stefan Mileschin

There's still a little bit of fight left in the GDDR5 ecosystem against the faster and more energy-efficient HBM standard, which has a vast and unexplored performance growth curve. The new GDDR5X standard offers double the bandwidth per-pin compared to current generation GDDR5, without any major design or electrical changes, letting GPU makers make a seamless and cost-effective transition to it.

In a presentation by a DRAM maker leaked to the web, GDDR5X is touted as offering double the data-rate per memory access, at 64 byte/access, compared to 32 byte/access by today's fastest GDDR5 standard, which is currently saturating its clock/voltage curve at 7 Gbps. GDDR5X breathes a new lease of live to the ageing DRAM standard, offering 10-12 Gbps initially, with a goal of 16 Gbps in the long term. GDDR5X chips will have identical pin layouts to their predecessors, and hence it should cost GPU makers barely any R&D to implement them.

http://www.techpowerup.com/217027/gd...entations.html