GDDR6 will of course be the successor to GDDR5, which is what you will find in many graphics cards these days. GDDR6 had been expected to have a speed of 14Gbps, but instead Samsung says they have reached 16Gbps with GDDR6!
Samsung announced this as part of their 36 products that were recognized as Innovation Awards ahead of CES 2018. The new GDDR6 memory is joined by Samsung’s Galaxy phones and new 8TB NGSFF NVMe solid state drive.
When it comes to GDDR6 Samsung says, “It processes images and video at 16Gbps with 64GB/s data I/O bandwidth, which is equivalent to transferring approximately 12 full-HD DVDs (5GB equivalent) per second”. So yeah it will be able to handle future 4K / 8K gaming.
If we compare it to GDDR5 which you will find in NVIDIA’s GTX 1060, GTX 1070, GTX 1070 Ti. On these cards it runs at 9Gbps, the GTX 1080 originally shipped with GDDR5 at 10Gbps. The GTX 1080 Ti and TITAN Xp have GDDR5X that runs at 11Gbps.
It is expected that NVIDIA’s “Volta” GeForce graphics cards to feature GDDR6. GDDR6 on a 256-bit memory bus will pack in 512 GB/s of memory bandwidth, while GDDR6 on a 384-bit memory bus will have a mind-blowing 768 GB/s of memory bandwidth.