HDDs still going strong: Western Digital announces 20 TB drives with OptiNAND flash memory
Western Digital is revitalizing the HDD technology with a new type of ePMR drive that adds an undisclosed amount of iNAND UFS memory dubbed OptiNAND to the mix. This should not be confused with previous hybrid drives (SSHDs). The conventional platters can store 20 TB, but the OptiNAND memory is used to store metadata from HDD operations, thus improving overall speeds and reliability.
Additionally, WD specified that the new OptiNAND tech will become the norm for all of its upcoming 20+ TB HDD models. The first 20 TB model is integrating 9 platters and the OptiNAND memory is apparently enabling 2.2 TB capacity per platter. Besides metadata, the OptiNAND memory also stores the Repeatable Run Out (RRO) that usually occupies several gigabytes and is generated during the manufacturing process, plus it can buffer out more data so the write-cache almost becomes redundant. Unfortunately, WD did not provide any figures in regards to performance improvements. Reliability should also see a boost, as the NAND memory is said to allow for up to 50x more data to be flushed out.
WD is currently sampling the 20 TB OptiNAND drives to select customers, but there is no word on pricing. The addition of the NAND memory, as well as upping the capacities beyond 20 TB should, however prompt a considerable premium.