Toshiba's recent acquisition of OCZ was a strategic investment. OCZ offers controller technology, a known brand, and marketing channels for client products. What followed was surprising. Instead of a rash of new products from OCZ, we were greeted by several announcements of new Toshiba designs. The new Toshiba PX02SS is another new entrant that rounds out Toshiba's enterprise product stack by fulfilling the demanding role of a heavy workload workhorse.
The PX02SS comes in the familiar 2.5-inch form factor and most notably features a 12Gb/s SAS3 connection. While the lower-endurance versions of the PX02 scale up to a maximum capacity of 1.6TB, the heavily overprovisioned PX02SS tops out at 800GB with a 15mm z-height. The smaller 100GB, 200GB, and 400GB capacities feature a slim 7mm case.
The PX02SS drive occupies the upper echelon of a four-tiered enterprise SSD product stack from Toshiba. The SAS3 PX02SM, evaluated here, provides similar characteristics with less endurance. The SAS3 PX03SN and SATA THNSNJ provide read-centric solutions for low-write-duty environments.
The PX02SS brings an impressive helping of random speed, providing 130,000/42,000 random read/write IOPS. Random speed is matched by an equally impressive 1,100 MiB/s in sequential read, but a slightly lower 410 MiB/s of sequential write speed sticks out on the spec sheet. The PX02SS is designed specifically for heavy write workloads in transactional environments; this lower sequential write performance will not have a significant impact on performance in its typical use-case.
Dual-port SAS provides multipath and failover capabilities for an SSD that delivers impressive performance and endurance. Toshiba leverages its proprietary Quadruple Swing by Code, a layered ECC system, to provide protection for user data. Power capacitors provide enough capacitance to flush data to the NAND in the event of host power loss. Toshiba covers the bases for data security compliance with available security models.
The read-oriented PX02SM also features the same 24nm eMLC NAND utilized on the PX02SS, but there is a smaller allocation of overprovisioning. The hefty 156 percent dose of extra overprovisioning on the PX02SS enables superior random write speed and a massive increase in endurance. The PX02SS features endurance ratings of 30 Drive Writes Per Day (DWPD). This endurance typically isn't seen outside of SLC products. The HGST SSD800MM clearly outpaces the PX02SS in a few performance metrics, but it falls short in endurance comparisons. The tremendous endurance of the PX02SS is a big differentiator among the current crop of 12Gb/s SSDs.
One indicator of this tremendous resilience is the rating of 5.4 PB of write endurance, measured per the JEDEC standard, for a 100GB SSD. This is an outstanding amount of endurance for such a small product, and it is nearly double the endurance of other competing solutions that feature twice the capacity. One could imagine these small volumes making their way into HDD caching solutions, a place where a small amount of flash can have a big impact on storage performance.
The Toshiba PX02SS offers the standard five-year warranty available with most enterprise SSD products. Today, we will compare it to the HGST SSD800M and its very similar PX02SM companion.