A few weeks ago, SK Hynix announced that it would start mass-producing 16 Gbps GDDR6 memory, and teased its plans to have the high-speed graphics memory show up in graphics cards by early 2018. Imagine our surprise, then, when GDDR6 made it first entry into SK Hynix's databook—but not quite at the blistering speed the company initially claimed.
The two GDDR6 products that SK Hynix lists in its databook operate at 12 Gbps and 14 Gbps, lower than the 16 Gbps that the company talked about in its initial news. Those are still respectable speeds, especially given the chips' 1.35V power requirements. It's worth noting that Micron has touted GDDR5X running at 13 Gbps, but the fastest shipping version of that RAM (in Nvidia's GeForce GTX 1080 Ti) only runs at 11 Gbps.
Although the seemingly-low speed of the new GDDR6 chips might be a little concerning, it's worth pointing out that neither GDDR5 or GDDR5X started their life at the blistering speeds we're seeing now. We expect that Hynix will tune its processes and ramp up clock speeds on GDDR6 as time moves on. After all, the GDDR5X spec has a theoretical ceiling of 14 Gbps, but we've yet to see any chips at that speed.
SK Hynix's updated catalog also lists upcoming GDDR5 variations with speeds ranging from 6 Gbps all the way up to 10 Gbps. The fastest memory chips in this lineup require a little more juice, drawing 1.55V. Those speeds are fast enough to blur the line between GDDR5 and GDDR5X, and they might bring GDDR5X levels of performance to more mainstream products in the future.
The databook from SK Hynix declares that all of these products will make their debut in the fourth quarter of 2017. Presumably, the company will release more information about its announced 16 Gbps GDDR6 with time. In any case, consumers will have to continue to pay close attention to the fine print when looking at graphics memory, because the distinctions between these various types of RAM may not end up as clear as one might hope.