Flash Storage Architecture: What’s Available and Why It Matters
The cost differential between hard disk and solid state drives is narrower than ever, further simplifying the calculus to determine what kind of storage to deploy on servers, the SAN and client devices across the enterprise.
But while costs have dominated the SSD narrative for more than a decade, it turns out that workload and application needs are becoming the true driver (sorry) for storage solutions, and in the high-speed world we live in, solid state is emerging as the primary medium regardless of price.
According to market-tracking firm DRAMeXchange, prices for MLC and TLC SSDs dropped by as much as 12 percent in the last quarter alone to range from 20 to 38 cents per GB, depending on the size of the drive. While this is still about four times the cost of hard disk storage, the speed of the SSD price decline and the fact that it shows no signs of subsiding — and in fact may even accelerate as demand continues to mount — means that price parity between the two is now well within the realm of possibility. This is particularly true for the “sweet spot” in solid state drive capacities of between 250 and 500 GB, which are expected to see high demand between now and 2022.
But if price was the only factor in storage decisions, the SSD would still be a rare sight at most data centers. The fact is that performance is the real prize in solid state deployments, something which the top drive manufacturers have not failed to notice. In fact, they are falling over themselves to create increasingly fast, increasingly dense products, even if they come at a price premium.
Samsung just raised the bar with a new 15.36 TB (yes, TB) drive called the PM1633a that marries third-generation 3D V-NAND with a 48-layer TLC architecture that enables 256 GB per die. This allows for a highly dense, three-bits-per-cell configuration, which does introduce a slight performance penalty over traditional 2D structures but this is diminished slightly by 16 GB of embedded RAM, a second tier of 16 die layers that provides an additional 512 GB of capacity. The drive is being sold with a 12 Gb SAS interface that enables 1.2 GB throughput and 200k/32k read/write IOPS.
Meanwhile, Toshiba is out with a smaller drive, only 1.92 TB, that is optimized for heavy read environments through the use of 15 nm MLC NAND flash for extra-low latency. The HK4R can handle three full wipes per day and can be configured with Trusted Computer Group (TCG) encryption and Toshiba’s Quadruple Swing-By Code (QSBC) error correction to protect sensitive data streams found in web and file workloads, media streaming and intermediary storage data services. The drive features a 6 Gb SATA interface to enable high throughput with low power consumption.
At the same time, Intel has teamed up with Micron with an eye toward integrating 3D NAND flash and crosspoint memory with the jointly developed “floating gate cell” architecture to push capacity to 10 TB or more. The companies are targeting MLC devices of 256 Gb and TLC at up to 384 Gb, both of which would fit within a standard drive footprint. Both companies are said to be of the opinion that standard 2D planar memory has reached its limits in terms of capacity, so the only place to go from here is 3D, which Micron has in spades.
Deploying solid state storage in place of hard disk has always been rather hard to quantify in enterprise settings. After all, how do you weigh the extra performance against the higher cost, particularly if the application at hand does not directly result in either lower costs or higher revenue?
But the fact remains that user expectations for speed and performance have never been higher, and services that get bogged down because applications have to wait on spinning disks and moving heads will see their audiences dwindle.
Fortunately for hard disk and tape, not all applications will require SSD-class performance but, increasingly, the critical apps that drive revenue and market share will. And equally as fortunate, it won’t cost a premium up front to put this level of storage in place.
Arthur Cole writes about infrastructure for IT Business Edge. Cole has been covering the high-tech media and computing industries for more than 20 years, having served as editor of TV Technology, Video Technology News, Internet News and Multimedia Weekly. His contributions have appeared in Communications Today and Enterprise Networking Planet and as web content for numerous high-tech clients like TwinStrata and Carpathia. Follow Art on Twitter @acole602.
