INTEL’S AWESOME SSD TECH
Will Optane drives finally arrive in 2017?
There’s a performance bomb heading for the solid-state storage market. That’s what we said this time last year. But it never happened. Not as we hoped, at least. To put it another way, Intel and Micron’s 3D XPoint memory technology, known as Optane when applied to Intel SSDs, never materialized.
Of course, 3D XPoint is a radical new type of memory tech, not an incremental improvement, so it’s not exactly shocking that it’s taking longer to hit the market than expected. But before we consider whether it will finally appear in 2017, it’s worth recapping why it’s so exciting.
3D XPoint is a non-volatile memory tech that’s claimed to be up to 1,000 times faster, 1,000 times more robust, and 10 times denser than the conventional NAND flash found in existing SSDs. Staggering stuff, but how does it work?
Unlike NAND flash, which is composed of memory cells consisting of gates in which electrons are trapped, 3D XPoint uses electrical resistance to store data. Each cell stores its bit of data via a subtle change in the conductive resistance of the cell material. A benefit is that this doesn’t require a transistor, and that means each cell can be smaller, so more can be packed into a given area of memory chip. That means higher densities and more storage.
The other major difference is the fact that 3D XPoint’s memory cells are addressable at the individual bit level. That’s a dramatic change from NAND, where whole blocks of memory, usually 16KB, must be programmed to save just one bit of data. The consequences for NAND flash are time-consuming read-modify-write cycles, and the need for complex garbage collection algorithms. That’s all gone with 3D XPoint, which should mean massively improved random access and IOPs performance.
Of course, much of that is theoretical. Early demos have shown random-access performance around five times faster than a current top SSD. Not quite 1,000. But imagine if Intel launched a CPU that was five times faster. Quite.
If that covers the technicalities, what’s the latest on any of us being able to buy an SSD with 3D XPoint tech? The only thing we know for sure is that Intel will be selling its 3D XPoint SSDs under the Optane brand. There has been some debate over what form that will take, including implications that it would be a whole new memory class, acting as a sort of high-speed cache, rather than mass storage.
More specifically, certain system configurations with an Optane drive will support a software-defined cache hierarchy, where the CPU’s addressable memory space is a combination of RAM and the SSD. But that tech is aimed more at heavy-duty database work than desktop PCs. With that in mind, Intel’s first step with Optane will be Optanebased testbeds designed for cloud computing. Intel is partnering with Facebook to test the technology, and it’s possible the latter is already using Optane to some extent.
However, the good news is that it’s probably conventional Optane SSDs that will hit the market first. That’s because using 3D XPoint as a system cache requires the creation and fine-tuning of a new software abstraction layer. Optane SSDs using the 3D XPoint technology could be plug and play with any modern PC. The only question is when that will happen. Back in mid-summer, some Intel road maps leaked, indicating a very-late 2016 launch. As we write these words in the dying days of 2016, that still hasn’t happened.
More recently, there has been talk of Optane drives launching with Intel’s new Kaby Lake seventh-generation Core processors. But just to really confuse things, those Optane drives are mooted at 16GB and 32GB capacities. In other words, so small that the implication is that they are cache drives, not mass storage SSDs.
The bottom line is that Optane isn’t out as we go to press, and it’s not clear when that will happen, or what form it will take. We still think it will be a killer technology—and, with any luck, 2017 will be the year it finally delivers. In the meantime, 2017 will see ever faster variants of what you might call conventional SSDs, but it will still look pretty exotic. Samsung’s new 960 Pro is likely a harbinger of things to come. M.2 and PCIe SSDs with GB/s of bandwidth will probably be fairly routine by the end of 2017.
SSDs continue to push forward both in terms of capacity and throughput.