SK Hynix recently updated its product catalog and announced the availability of its eight gigabit (8 Gb) GDDR6 graphics memory. The new chips come in two SKUs and three speed grades with the H56C8H24MJR-S2C parts operating at 14 Gbps and 12 Gbps and the H56C8H24MJR-S0C operating at 12 Gbps (but at higher voltage than the -S2C SKU) and 10 Gbps. Voltages range from 1.25V for 10 Gbps and either 1.25V or 1.35V for 12 Gbps to 1.35V for 14 Gbps. Each 8 Gb GDDR6 memory chip holds 1 GB of memory and can provide up to 56 GB/s of per-chip bandwidth.
While SK Hynix has a long way to go before competing with Samsung’s 18 Gbps GDDR6, its new chips are significantly faster than even its latest GDDR5 chips with the company working on bringing 9 Gbps and 10 Gbps GDDR5 to market. As a point of comparison, its fastest 10 Gbps GDDR5 would have a per chip bandwidth of 40 GB/s versus its 14 Gbps GDDR6 at 56 GB/s. A theoretical 8GB graphics card with eight 8 Gb chips running at 10 Gbps on a 256-bit memory bus would have maximum bandwidth of 320 GB/s. Replacing the GDDR5 with 14 Gbps GDDR6 in the same eight chip 256-bit bus configuration, the graphics card would hit 448 GB/s of bandwidth. In the Samsung story I noted that the Titan XP runs 12 8 Gb GDDR5X memory chips at 11.4 Gbps on a 384-bit bus for bandwidth of 547 GB/s. Replacing the G5X with GDDR6 would ramp up the bandwidth to 672 GB/s if running the chips at 14 Gbps.
|Chip Pin Speed||Per Chip Bandwidth||256-bit bus||384-bit bus||1024-bit (one package)||4096-bit (4 packages)|
|10 Gbps||40 GB/s||320 GB/s||480 GB/s|
|48 GB/s||384 GB/s||576 GB/s|
|14 Gbps||56 GB/s||448 GB/s||672 GB/s|
|16 Gbps||64 GB/s||512 GB/s||768 GB/s|
|18 Gbps||72 GB/s||576 GB/s||864 GB/s|
|HBM2 2 Gbps||256 GB/s||256 GB/s||1 TB/s|
GDDR6 is still a far cry from High Bandwidth Memory levels of performance, but it is much cheaper and easier to produce. With SK Hynix ramping up production and Samsung besting the fastest 16 Gbps G5X, it is likely that the G5X stop-gap will be wholly replaced with GDDR6 and things like the upgraded 10 Gbps GDDR5 from SK Hynix will pick up the low end. As more competition enters the GDDR6 space, prices should continue to come down and adoption should ramp up for the new standard with the next generation GPUs, game consoles, network devices, ect. using GDDR6 for all but the highest tier prosumer and enterprise HPC markets.