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- Rich Castagna, Vice President of Editorial
"Is it live, or is it Memorex?"
In those old TV commercials, Ella Fitzgerald hit a high note that shattered a glass -- and then the same note was played back on tape with the same shattering effect. While Memorex is little more than a memory now, there are still some paradigm-shattering events grabbing data media market headlines.
NAND flash technology has been adopted at a clip far faster than anything else in the pokey, snail's pace world of storage technology. There are a number of reasons for NAND's meteoric rise, but it's mainly because flash technology is showing up in nearly every storage product sold these days for one reason: pure speed. Early on, because it was the priciest storage medium on the market, storage vendors found clever ways of tapping a relatively small amount of flash to noticeably crank up performance -- enough so, in some cases, to remove storage as the perennial performance bottleneck.
Having significantly revved up storage performance, storage users wanted -- what else? -- more performance. Greater demand and increased production helped take some of the air out of inflated flash prices and, before you noticed, all-flash storage arrays were flying off showroom floors.
End of the solid-state story? Hardly
As flash quickly developed into an auxiliary cache for server DRAM, one thing became clear: In a race with DRAM, as much as flash huffed and puffed its way through data, it finished a distant second. So, if flash is a lot faster than hard drives but lumbering compared to DRAM, there had to be a storage technology that split the difference, right?
And now there is one. Actually, there are several candidates to fill that gap, all of which have been around for some time -- but they've mostly been prisoners of R&D labs and more like science fair projects than products.
Two key recent developments clearly show there's solid-state life beyond flash, and it's not just a matter of faster, bigger and more durable. The Micron/Intel partnership's recent rollout of 3D XPoint technology and IBM's tweaks to phase-change memory (PCM) are evidence that, while NAND flash technology ushered in the solid-state era, it is really just the harbinger of products to come that will challenge the traditional concepts of memory and storage.
The astounding thing about those two techs is how what those companies demoed was a zillion times faster than the NAND flash technology in use today, would last a billion years longer and could handle a gazillion writes. I may be exaggerating a bit with those numbers, but you get the picture.
The end of latency as we know it
3D XPoint's developers from Intel and Micron say it will run circles around NAND flash -- about 1,000 circles to every one NAND completes. And they claim durability of the same ratio -- 1,000 times that of NAND flash.
For their part, IBM's brainiacs made a PCM breakthrough by finding a way to stuff three bits of data into a single cell -- just as the NAND flash masterminds did to boost capacities, cut costs and make flash accessible to all. IBM doesn't tout XPoint-like speeds and feeds, but it does say PCM is hundreds of times faster than NAND flash for both reads and writes. And IBM cites an anticipated "10 million write cycles" as its anticipated durability.
Either way you look at it, these new techs are making NAND flash technology look like Roger Bannister, the guy who broke the four-minute mile: fast in his day, but slow compared to Usain Bolt.
New chips coin new terminology
It's a little tough to grasp such staggering stats when so many of us are still trying to put NAND flash performance into perspective. But this new stuff is fundamentally different than the solid-state we're using today, as it's nearly as close to memory as it is to persistent storage. That distinction has resulted in a new term for these emerging techs: storage-class memory. Sort of an odd term, yet it somehow seems a fairly accurate and appropriate description.
The encroachment of storage on memory's turf really started a few years back when the first DIMM-based solid-state products appeared. Viking Technology DIMM-slot flash was an interesting product that helped bridge the conceptual gap between memory and storage, but it was really flash with a SATA interface getting its juice from a DIMM slot. Diablo Technologies took the concept a step further with its Memory Channel Storage, providing access to flash storage via the server processor's memory channel. This technology -- NVDIMM or non-volatile DIMM -- had an instant application in mirroring server memory, which allowed for nearly instantaneous recoveries of cached data and applications if DRAM lost power.
Tiered memory and a new storage model
Solid-state is doing stuff that hard disk drives could never do -- at least not at an acceptable pace -- and developments such as those from IBM and Intel/Micron promise to erase the line between storage resources and memory. Given their performance, these emerging technologies will allow tiering and expansion of memory -- not at the speeds of DRAM, perhaps, but also not at the price of current system memory modules. This will put more processing in memory and memory-like resources, reducing the number of times a server will have to fetch data from persistent storage.
Oddly, the expansion of solid-state's role is likely to be something of a boon to hard disk manufacturers. After all, all that data will have to come to rest somewhere, and while the latest high-capacity NAND flash devices may fill that role, spacious hard disks can do it at a fraction of the cost.
What do these new solid-state developments mean to you? If your current storage configuration is humming along and keeping up with (or surpassing) your server and network performance, these developments mean nothing. But if NAND flash technology hasn't quenched your app's thirst for performance, be patient, help is on the way.
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