Over at the Flash Memory Summit, SK Hynix presented a new flash technology that it's branding 4D NAND. It's more marketing than something truly revolutionary, Tom's Hardware was there and points out that SK Hynix's 4D NAND is quite similar to technology made by Intel and Micron, albeit with a couple of other features mixed in. The 4D NAND from SK Hynix pairs Charge Trap Flash (CTF) design with the firm's currently used Periphery Under Cell (PUC) technology.
SK Hynix's new 4D NAND uses a charge trap design, just like the flash produced by Samsung and WD/Toshiba. SK Hynix has used Charge Trap Flash (CTF) designs for several years, so it isn't new, and currently Micron and Intel are the only two flash-fabbers using floating gate technology. Intel and Micron plan to diverge on their flash development efforts after their next-gen flash comes to market, after which Micron will use its own 'Replacement Gate' technology, which is simply a re-branded Charge Trap Flash design. In other words, Intel will soon be the only flash producer using floating gate technology.
In its presentation, SK Hynix revealed it sees a path for 4D NAND up to more than 500 layers. At present, SK Hynix's most advanced flash memory uses 96 layers. A timeline wasn't provided, flash with that many layers is still years away. The first 4D NAND from SK Hynix will sample in Q4 2018, it will be a 96-layer TLC chip with a capacity of 512Gb. A QLC-based version is expected in the second half of 2019.
SK Hynix promises 4D NAND will offer a 30 percent reduction in chip size versus its current 3D NAND, a 30 percent increase in write performance, a 25 percent increase in read performance, and a 150 percent jump in bandwidth/power.