The SanDisk X210 SSD is a SATA 6Gb/s SSD that comes in a 2.5" form factor with a slim 7mm z-height. The X210 is powered by the 8-channel Marvell 9187 controller, in conjunction with SanDisk 19nm ABL NAND. The X210 is available in capacities of 128, 256 and 512GB, and features sequential speeds of 505/470 MB/s and 89,000/60,000 random read/write IOPS.
The emergence of the 'business class' of SSDs signifies the continuing evolution of the SSD market. As the SSD market matures, a drive for nearly every use-case has come forward. The X210 SSDs are designed for read intensive applications that run the gamut from business notebooks and client computing to server operating system loads in datacenter and server markets.
By addressing micro and entry-level servers in data centers, SanDisk is tapping into the burgeoning mainstream enterprise market. As a foundry owner, SanDisk can provide lower costs than many of their competitors.
Balancing the performance requirements for server use with the demands of business laptop and mobile applications is a tricky endeavor. Adding the DevSleep feature addresses the mobile sector, while nCache addresses latency and endurance concerns. nCache creates a layer of SLC flash inside each NAND die that is utilized as a fast non-volatile write cache, thus reducing wear on the underlying MLC.
Like many enterprise SSD manufacturers, SanDisk has chosen to stick with conservative endurance specifications. With a blanket 80 TBW (TeraBytes Written) rating for all capacities of the SSD, one could assume that the larger 256 and 512GB X210's can easily provide more resilience due to the typical scaling of endurance with capacity.
The new read-centric class of SSD's provides a cheaper alternative to the more robust high-endurance SSDs geared for heavy write workloads. However, the lower price point provides an opportunity for users to tailor the SSD to their workload by adjusting the amount of performance and endurance through the simple addition of extra spare area. This extra spare area, referred to as overprovisioning (OP), sacrifices a portion of the addressable disk space in exchange for increased performance.
One of the positive aspects of leveraging extra overprovisioning is also the increase in IOPS per Watt. While the massive gains in power efficiency and performance are the driving force behind the SSD explosion in the datacenter, the endurance concerns are one of the factors holding them back. With the addition of extra overprovisioning users can address the endurance concerns, and add to the performance and efficiency of the SSD in one simple move.
Many considerations factor in to just how much extra overprovisioning to add to the SSD to attain the correct performance and endurance profile. Today we are keeping it simple, testing with the base settings for the SSD and with an extra 20% of overprovisioning, but users can utilize many varying levels to address their performance challenges.