SSDs Have Bleak Future, Says Researchers

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By Kevin Parrish
published

SSD performance will only get worse as NAND flash circuity gets smaller.

SSDs are seemingly doomed. Why? Because as circuitry of NAND flash-based SSDs shrinks, densities increase. But that also means issues relating to read and write latency and data errors will increase as well.

"This makes the future of SSDs cloudy," states Laura Grupp, a graduate student at the University of California, San Diego. "While the growing capacity of SSDs and high IOP rates will make them attractive for many applications, the reduction in performance that is necessary to increase capacity while keeping costs in check may make it difficult for SSDs to scale as a viable technology for some applications."

To prove this theory, Grupp teamed up with Steven Swanson, director of UCSD's Non-Volatile Systems Laboratory, and John Davis of Microsoft Research. Using PCIe-based flash cards with a channel speed of 400 MBps based on the Open NAND Flash Interface (ONFI) specification and a standard 96 NAND flash dies, they tested 45 different NAND flash chips from six different vendors that ranged in size from 72-nm to 25-nm.

The group discovered that write speed for pages in a flash block suffered "dramatic and predictable variations" in latency. Even more, the tests showed that as the NAND flash wore out, error rates varied widely between devices. Single-level cell NAND produced the best test results whereas multi-level cell and triple-level cell NAND produced less than spectacular results.

With the testing information at hand, the group fast-forwarded to the year 2024 when NAND flash circuitry is expected to be only 6.5-nm in size. They predicted that read/write latency will double in MLC flash and increase more than 2.5 times for TLC flash. Yet SSDs at that time are expected to feature capacities of 4 TB when using MLC flash, and 16 TB when using TLC flash.

"It's not going to be viable to go past 6.5-nm," Grupp said. "2024 is the end. [People] are used to working with technology that continues to just get better, but with NAND flash we're going to be facing trade-offs as it evolves."

To read the full report, head here.

Kevin Parrish
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209 Comments Comment from the forums
  • divhon
    truly yours,

    THAILAND HDD manufacturers
    Reply
  • samuelspark
    2024? Our SSD's are still good for 12 years..
    Reply
  • eddie d
    They will find a way. LCDs are supposed to suck, and look at all the tom-foolery LCD manufacturers have gone through to make them compete with Plasma and CRT.
    Reply
  • serendipiti
    Should I worry about the sun's collapse ?
    Double the latencies when on 4 TB capacity ? that's still in the microseconds range...
    Mechanical disks need to rely on caches (try disabling the disk's cache on device properties in windows, and see), and it's completely impossible to go beyond milliseconds (head's weight - movement speed - strength are related to materials we have, and discovering such a material (that could make possible to go beyond ms) would change our whole lives (but not for having better HDD, we would have better cars, planes...).
    SDD based on nand flash, memristors or whatever else are here to stay. I agree in some scenarios HDDs still perform best... but the trend will be towards SSDs: because (to make SSDs) you don't need to master another completely different technology (to make HDDs), because it's hard to fit an HDD into a SoC...
    Reply
  • The term SSD could be applied to any solid-state memory based storage device, not just NAND flash based ones. It seems shortsighted to claim the doom of SSDs based on the short comings of one memory type. What about PCM, ReRAM and STT-RAM based SSD's?
    Reply
  • nofun
    "The automobile is only a fad, but the horse is forever."

    In the future we will likely see a hybrid approach, with a small SSD (possibly directly socketed into the mobo) for the OS and a few common apps. This will be invisible to the user, just as RAM is invisible to them now. The first chipset to really pioneer this approach will gain an advantage over the competition, and you can bet they are already working on it. The Z68 was the first step, next there will be a socket on the mobo for a small NAND hard drive with the OS pre-installed and some extra room. The BIOS will know that when this boot drive is detected to boot from it rather than a traditional HDD, and the OS will know to keep it hidden from the user.
    Reply
  • wiyosaya
    Pure speculation from an "expert." I think it is rather annoying that there is a lot of obvious things "discovered" by "scientific" researchers these days, and it somehow passes as newsworthy.

    What cannot be seen at this point is all the improvements in the technology that real researchers are working on and will continue to develop to overcome all the problems cited by this "expert." I am sure that real researchers are aware of the problems pointed out by this "expert," and are already looking for solutions.

    By the time that 2024 comes along, who knows what form mass storage will have.
    Reply
  • frenchy
    An interesting article but 12 years from now is a long time in the computer world. It could very well be that something new completely replaces SSDs. I would actually be surprised that something doesn't replace it.
    Reply
  • Come on Tom, this is a silly article. Assuming the problems increase with no technology increase other than stumbling along the shrinking die path; to illustrate a cloudy future for SSDs? Really? On so many levels this is absurd.
    Reply
  • tomfreak
    Sometimes I wonder, desktop HDD are not limited to power consumption, but why arent the HDD manufacturer push 10K RPM HDD down to mainstream to "slow the SSD" adoption . Surely the latency gap would have improved significantly, 8.9ms vs 4.0 seek time. It may not reach the SSD ones, but it is still better to delay the SSD getting into mainstream. While many of us like the capacity of HDD, but we I would prefer having slighly smaller 500GB with boost speed over the 2TB ones. The size of the mainstream SSD are still less than 64GB, win7 64bit takes up almost half of it, so the leave not much room for games/other thing.
    Reply