Last November, Intel introduced a new enterprise-oriented SSD based on proprietary controller technology. The DC S3700 uses 25-nm MLC NAND and is aimed at high-performance servers. At over $2 per gig, it's also quite expensive. Fortunately, budget-conscious server builders now have another option: the DC S3500, which pairs the same controller with 20-nm flash memory.
Introduced today, the DC S3500 is designed for read-intensive server applications. While its write speeds are notably lower than those of the S3700—particularly with random I/O—its prices are quite a bit cheaper, as well. Here are the specifications for the full lineup, whose prices stray close to $1 per gig.
|Capacity||Max sequential (MB/s)||4KB random (IOps)||Max writes||Price|
Those are all 2.5" drives, by the way. The S3500 is also available in a smaller 1.8" form factor, albeit with more limited capacity options. The smaller drives cost $10 more than their 2.5" counterparts and are confined to 80, 240, 400, and 800GB flavors. Their performance specifications don't skip a beat, though.
Intel emphasizes the performance consistency of the DC S3500, which carries an interesting quality-of-service rating. With 4KB random I/O at a queue depth of one, Intel claims that 99.9% of read requests will be serviced in 500 µs or less. The same percentage of writes will be completed within 5 ms.
In addition to slower write speeds, the DC S3500 also has lower endurance than its pricier sibling. The S3700 is rated for 10 full drive writes per day for five years. The total-bytes-written figures attached to the S3500 models work out to less than a full drive write per day over the same period. The drive still offers five years warranty coverage, though, and the write totals are more generous than those attached to consumer-grade SSDs.
The DC S3500 also has a number of features not typically found in client SSDs. Intel has implemented end-to-end data protection, data redundancy, and power-loss protection. The drive won't shut down until its write cache is fully cleared. It also reports any uncorrectable errors to the host. 256-bit AES encryption is supported, of course.
Also worth noting is the DC S3500's conservative power draw. The thing pulls just 0.65W at idle. Read workloads push power consumption to 1.3W, Intel says, and the drive can ramp up to 5W while writing. Even a few watts make a difference when you're running a datacenter loaded with multiple racks of drives.