SK Hynix has revealed its new enterprise solid state drives based on 72-layer 512 Gb 3D TLC NAND flash dies paired with the company’s own in-house controller and firmware. The SK Hynix eSSDs are available in a traditional SAS/SATA interfacing product with capacities up to 4TB and a PCI-E variant that comes in ‘above 1TB.” Both drive types are reportedly being sampled to datacenter customers in the US.
SK Hynix has managed to double the capacity and improve the read latency of its new 512 Gb 72-layer NAND flash over its previous 256 Gb 72-layer flash which debuted last year. The eSSD product reportedly hits sequential read and write speeds of 560 MB/s and 515 MB/s respectively. Interestingly, while random read IOPS hit 98,000, random write performance is significantly lower at 32,000 IOPS. SK Hynix did not go into details, but I suspect this has to do with the tuning they did to improve read latency and the nature of the 72-layer stacked TLC flash.
Moving up to the PCI-E interfacing eSSD, customers can expect greater than 1TB capacities (SK Hynix did not specify the maximum capacity they will offer) with sequential reads hitting up to 2,700 MB/s and sequential writes hitting 1,100 MB/s. The random performance is similar to the above eSSD with write performance being much lower than read performance at 230K read IOPS and 35K write IOPS maximum. The greatly limited write performance may be the result of the drive not having enough flash channels or the flash itself not being fast enough at writes which was a tradeoff SK Hynix had to make to hit the capacity targets with larger capacity 512 Gb (64 GB) dies.
Sadly, SK Hynix has not yet provided further details on its new eSSDs or the 3D-V4 TLC NAND it is using in the new drives. SK Hynix continuing to push into the enterprise storage market with its own SSDs is an interesting play that should encourage them push for advancements and production efficiencies to advance NAND flash technology.
