Choosing The Right SSD For The Data Center: 5 Top-Notch Picks10:00 AM EST Wed. Mar. 20, 2013
As the cost of solid-state drives falls, SSDs have become a more cost-effective way to increase performance-hungry enterprise applications' response times. There are important differences between SSD products, and between SSDs and their magnetic counterparts, so cost alone shouldn't drive purchasing decisions. First, flash-based hard drives wear out because the oxide layer that stores its binary data degrades with every program/erase (P/E) cycle. All SSDs use NAND flash; some use the more durable SLC NAND, while others use the less expensive MLC NAND. Most SLC memory supports about 50,000 P/E cycles, while MLC generally lasts about 5,000 cycles. Drive vendors employ "wear-leveling" techniques that spread P/E cycles across all cells to prolong a drive's usable life.
As Storage Week 2013 continues, the CRN Test Center evaluates five solid-state drives that recently hit the market, sizing up their place in the enterprise. All drives conform to the 2.5-inch form factor and comply with the SATA 3.0 specification, which performs at a maximum theoretical transfer rate of 6 Gb/s.
Don't let the numbers fool you. Although Kingston's SSD Now series includes 200- and 300-series solid-state drives for businesses and consumers, the company's E100 models are anything but low-end. The E stands for enterprise, and these drives are designed for use in data centers and other continuously operating environments. Kingston rates its SATA 3.0 E100 drives at 500 MB/s for sequential writes and 535 MB/s for sequential reads, which is on par with most other drives in this class. Its reported transaction rate varies by drive size and maxes out at a sustained rate of 59,000 IOPS for random reads and 73,000 for random writes. As for endurance, E100-series drives set aside 20 percent of drive capacity for wear-leveling and are rated at 30,000 P/E cycles over their lifetime. They also are covered by a three-year warranty. They're available in 100-GB, 200-GB and 400-GB capacities.
The latest solid-state drive line from SSD pioneer Intel is the S3700 Series, a series of super-fast, super-durable MLC SATA 3.0 drives for enterprise applications. They're available in 100-GB, 200-GB, 400-GB and 800-GB capacities in the 2.5-inch form factor, and 200-GB and 400-GB in the 1.8-inch size. All S3700 series SSDs are rated at 500 MB/s for sequential reads and 460 MB/s for writes. Random transactional performance is rated at 75,000 IOPS for reads and 36,000 for writes. Beyond its most durable competitors, Intel's S3700 drives are rated to deliver 10 drive writes per day for "over five years." Intel's S3700 drives are covered by a five-year warranty.
The only non-SATA drive in the lot was the s840 Series SAS SSD serial-attached SCSI drive from STEC. Based in Santa Ana, Calif., the SSD OEM positions its drives as ideal for server and Tier-0 storage arrays and claims throughput as high as 120,000 IOPS. Available in 200-GB, 400-GB and 800-GB capacities, this 6Gb/s dual-port drive uses MLC flash technology to deliver sustained throughput for reads of 500 MB/s and for writes of 300 MB/s. More significant is its transaction rate, which STEC puts at 115,000 IOPS for sequential reads and 104,000 for writes, and maximum random rates of 75,000 for reads and 11,000 for writes. The drive incorporates custom ASICs, proprietary controllers and wear-leveling techniques that allow for 10 full-capacity writes per day for throughout on its five-year warranty period.
Memory-maker Micron also backs up its enterprise-grade SSD for five years and warrants it to perform 10 drive fills per day during that period. We're referring to the Enterprise SSD P400m, its recently released series of high-performance MLC SATA 3.0 SSDs that come in 100-GB, 200-GB and 400-GB capacities. According to Micron, the P400m controller hosts its proprietary performance and reliability firmware, which closely integrates the NAND flash device and controller to produce an MLC-based SSD that maximizes endurance. The 200-GB tested model is rated to deliver 380 MB/s for sequential 64-KB reads and 310 MB/s for writes. For random 4-KB reads, the drive delivers 54,000 IOPS and 26,000 for random writes.
With the 840 Pro Series, Samsung offers consumers and professionals a line of MLC SSDs that are rated to deliver transfer speeds in excess of 500 MB/s, roughly doubling those of the previous generation. According to Samsung, the key to its performance is its three-core MDX controller, which now incorporates ARM Cortex processor cores. Having three cores lets the controller read with one core, write with another and collect garbage with the third. Rated performance of the 512-GB tested drive is 540 MB/s for sequential reads and 520 MB/s for writes. Random transactional performance peaked at 100,000 for reads and 90,000 for writes. The drive is also available in 256-GB and 128-GB capacities. Samsung drives also include feature-rich data-migration software that uniquely identifies videos, ISOs and other large files for deletion or migration to separate media.
Storage Week continues tomorrow with a close look at CRU DataPort's latest highly secure data storage appliance. Also don't miss the CRN Test Center's coverage of Three Wise NAS Devices.