Consumer-grade SSDs started making the transition to 25-nm NAND early last year. We saw enterprise-oriented drives based on MLC flash make the jump, as well, but nothing on the SLC front—until now. Hitachi has begun shipping the "industry's first" enterprise-class SSD with 25-nm SLC NAND.
The Ultrastar SSD400S.B was developed in conjunction with Intel, which fabricates the drive's memory chips. Intel's controller tech is also a part of the drive, although it's been grafted to Hitachi's interface logic to offer 6Gbps SAS compatibility. Hitachi says the new Ultrastar can sustain read and write speeds of 536 and 502MB/s, respectively. The drive is rated for 57,500 random-read IOps and 25,500 IOps with random writes. Those random I/O performance ratings are only slightly improved over the Ultrastar SSD400M, which is essentially the same drive with Intel's enterprise-grade MLC NAND. That model can only reach 495MB/s with sustained reads and 385MB/s with writes, though.
SLC NAND has been prized more for its superior endurance than faster performance, and the latest Ultrastar should deliver on that front. While its MLC-based sibling is expected to burn out after writing 7.3 petabytes worth of data, the Ultrastar SSD400S.B can purportedly process 35 petabytes of writes, nearly a five-fold increase in endurance. Interestingly, that 35-petabyte rating is mirrored by the old SSD400S, which uses 34-nm SLC flash. If any die-level endurance was lost in the transition from 34- to 25-nm flash, the drive is making up for it elsewhere.
The Ultrastar SSD400S.B is available in 100, 200, and 400GB capacities. Full-disk encryption is optional, and the warranty is five years or 35 petabytes—whichever comes first, presumably. There's no mention of pricing, but if you have to ask, you probably can't afford one. Amazon has the 400GB version of the old Ultrastar SSD400S listed at over $5,000.