Hot on the heels of releasing its 335 Series solid-state drive for desktop users, Intel has uncorked another new SSD. The DC S3700 is aimed at data center applications, and unlike 335 Series, it has one of Intel's own controllers under the hood. This chip is a brand new design, Intel's first since the controller behind the original X25-M SSD. That chip was refreshed for several generations of consumer and enterprise drives and last took root in the server-oriented 710 Series, which will be slowly phased out in favor of the DC S3700.
The new controller features eight NAND channels, matching the number on most contemporary controllers. Up to eight NAND dies can be addressed per channel, bringing the controller's maximum capacity up to 64 dies. The controller has a 6Gbps Serial ATA interface, and a gig of DRAM rides shotgun.This DRAM cache never stores user data but is instead used for context and indirection tables.
That detail is important in light of the DC S3700's power-loss protection, which uses multiple onboard capacitors to ensure that in-flight data is safely written to the flash in the event of a power failure. The drive features a built-in check that probes these capacitors on boot and periodically during operation. If any problems are detected, the drive notifies the host and disables its write buffer to prevent potential data loss.
Intel has also integrated end-to-end data protection. The DC S3700 applies a CRC to incoming writes, a value that stays with the data in the NAND and is checked when that data is read. All of the DC S3700's memory has ECC, Intel says, and the controller also supports LBA tag validation. 256-bit AES encryption has been thrown in for good measure, as well.
As one might expect, Intel has lined the DC S3700 with its own NAND. The drive features 25-nm MLC chips from Intel's stash of high-endurance flash. Thanks to these chips, plus careful firmware tuning, the SSD can purportedly endure 10 full drive writes a day for five years, the length of its warranty. That endurance limit applies to random-write workloads; Intel tells us the DC S3700 could last twice as long with sequential write workloads.
|Capacity||Max sequential (MB/s)||Max 4KB random (IOps)|
2.5" versions of the DC S3700 will come in four flavors between 100 and 800GB. They all promise sequential read speeds of 500MB/s and random 4KB read speeds of 75,000 IOps. Write performance varies based on the capacity, with the 100 and 200GB models lagging behind their higher-capacity counterparts. The performance ratings are substantially higher than those of the old 710 Series, particularly for writes.
Intel has focused on consistency with the DC S3700. The drive's performance should vary by no more than 15% from the values in the table above, Intel says. Users can expect average read and write latencies of 50 and 65 µs, respectively, and Intel claims the drive's latency is less than 500 µs 99.9% of the time.
Enterprise-grade SSDs don't come cheap, but the DC 3700 costs 40% less than its predecessor. Intel is charging $235 for the 100GB model, $470 for the 200GB, $940 for the 400GB, and $1,880 for the 800GB. It will also offer a couple of 1.8" versions intended for blade and micro servers. These bite-sized drives will weigh in at 200 and 400GB and cost $495 and $965, respectively. Drives are sampling now, with volume production expected to begin in the first quarter of next year.
Naturally, we couldn't resist asking Intel whether its new controller ASIC would make its way into consumer-oriented drives. There's apparently nothing to stop that from happening, although Intel has no plans to announce on that front right now. The firm did point out that some of the controller's enterprise-specific features aren't really necessary on mainstream SSDs. Of course, Intel is no stranger to disabling various on-chip features to target different markets.