Hybrid drives in your future?

Hybrid drives in your future?

Summary: Hard disk capacity is cheap but slow. Flash drives are fast but costly - and we don't make enough flash to replace hard drive capacity. Hybrids - flash + disk - is industry's answer. Will it be yours?

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Hard disk capacity is cheap but slow. Flash drives are fast but costly - and we don't make enough flash to replace hard drive capacity. Hybrids - flash + disk - is industry's answer. Will it be yours?

Even with recent price drops in anticipation of Toshiba's new Fab 5 coming on line, the cheapest flash GB costs 30x the largest disks. And for large reads and writes, disk performance is competitive.

So disks aren't going away.

But the performance benefits of flash SSDs for other workloads are stunning. The entire industry, from drive vendors to the largest array vendors, are racing to find the sweet spots where performance is maximized at minimum cost.

One of those spots is the hard drive.

Hybrid tea leaves Seagate already has hybrid drives with their Momentus XT. I used them in notebooks and found they provided more performance, but the stingy 4GB of flash limited their value.

But industry rumors claim that Seagate is getting ready to roll out enterprise hybrids: 10k drives with 8 to 16 GB SLC flash caches and better optimized data placement software. The sales pitch: "get SSD-like performance for little more than a 15k drive price."

Toshiba is also looking to enter the market. Commenting recently Hironobu Nishikori, VP of Toshiba's Semiconductor & Storage Products said,

. . . optimization of data placement is what we are struggling with most now. Especially, it is now a great challenge to realize a high storage capability while considering security and power saving issues. . . .it is a great advantage to have both HDD and NAND flash memory businesses.

Toshiba invented flash and then doggedly invested in the technology for 20 years before its "overnight" success in the last decade. They can do as much as Seagate to exploit the hybrid architecture. And if they want to grow their shrinking disk market share, they need to.

Will it fly? What isn't clear is market acceptance. In recent research by my firm, only 7.5% of respondents planned to migrate their applications to SSDs. And, of course, even fewer consumers are using them.

Which means the market is still wide open for a hybrid solution. What will a successful hybrid look like?

Critical points:

  • Performance. The hybrid needs to be within 20% an SSD in everyday performance. That means the flash cache has to be large enough and smart enough to identify and store 80% of what the average user accesses everyday. 4GB is too small, 8GB will satisfy casual users, and power users will need 16-32GB. Linux servers will want 8-16GB; Windows servers 16-32GB.
  • Price. Flash is expensive and so is the integration work. Vendors need to make a profit while consumers need to see value. The price uptick is easiest to justify at higher price points, so stick large and/or fast drives.
  • Cost+ pricing. The temptation is to look at SSD pricing and come in at, say, half that. Don't do it. Disks are the default option for most consumers and enterprises - and you want to keep it that way. Take some extra margin, but don't go crazy. This is a new segment and you're in it for the long haul.
  • Reliability. Use MLC for consumers - they don't care. But enterprise buyers are wary of endurance problems so put SLC in those. Use the flash as a cache, not as a tier, for data protection, so the drive keeps working even if flash fails. And keep your standard warranty.
  • Software. Ship with a standard set of caching rules, but add a tuning utility. It will be a selling point and gives sysadmins extra motivation to understand what your shiny new hybrid can do.

The Storage Bits take Flash SSDs are great - if you can afford them. Hybrids are the Next Big Thing in storage devices because they can give some of the key benefits of SSDs - such as fast boots and app starts - without sacrificing the capacity that our music, photos and videos gobble up.

The disk drive is far from dead. Hybrid drives will keep them spinning for decades to come.

Comments welcome, of course. I expect to see announcements starting next month. No NDAs were violated in the writing of this post.

Topics: Storage, CXO, Hardware, Toshiba, IT Employment

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12 comments
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  • Yeah, but what about the writes!

    Hybrids are only read optimized. I am starting to think they are a fad.

    Also, what do you mean by "Price. Flash is expensive and so is the integration work. "?
    b4real@...
    • RE: Hybrid drives in your future?

      @b4real@... - The optimal hybrids would be an OS specific partition as flash (for fast read speed) and a data partition as disc (for faster write speeds).<br><br>Linux already supports this via the setup process when you configure the partitions manually, don't believe OS X does this, and Microsoft Windows can support this but it isn't available as part of the install process even though it's been a much requested capability (separate OS data from the Program Files and Users data). On Windows it *Can* be done, but then you can't upgrade the OS to the next version, you have to put it back the way Windows expects to find it.
      PollyProteus
    • RE: Hybrid drives in your future?

      @b4real@... I thought about getting into the write caching issue and maybe I should have. For years Windows machines had write caching turned on by default, even though power failures would corrupt cached data that hadn't been written to disk. It rarely became an issue.<br><br>The same is true for consumer hybrids, especially those in notebooks. The power won't fail suddenly - the battery, right? - so there will always be time and power to write to disk. <br><br>The enterprise-class solution is more complex, but solvable with tantalum capacitors to provide temporary power to destage any cached but not written to disk.<br><br>However, Seagate's MomXT architecture doesn't use the flash as a simple cache, so they don't have to worry about those issues - including improved write speeds. Their 1st gen architecture is quite conservative, using flash only as a parking place for already-written data that the adaptive memory controller decides can be better retrieved from flash. They have much design freedom to improve on that and I trust they shall.
      R Harris
  • RE: Hybrid drives in your future?

    I normally find your articles informative and even witty, but I am aghast at seeing a reference to HDs as slow and Flash as fast. That is exactly opposite of reality.

    RAM is fast, Flash is slow, slow, slow... I'm not talking theory here, or manufacturers quotes, I'm talking real world, every example I have ever come across, and unfortunately I have been in this business as long as you.
    mithraigor@...
    • RE: Hybrid drives in your future?

      @mithraigor@...

      So what are you saying? Are you saying that when RAM becomes non-volatile (STT-RAM) then flash will be obsolete?
      josh92
      • RE: Hybrid drives in your future?

        @josh92
        Thanks!
        R Harris
    • RE: Hybrid drives in your future?

      I normally find your posts informative and even witty, but I am aghast at seeing a reference to Flash as slow and RAM as fast. That is exactly opposite of reality.<br><br>L3 Cache is fast, RAM is slow, slow, slow... I'm not talking theory here, or manufacturers quotes, I'm talking real world, every example I have ever come across, and unfortunately I have been in this business as long as you.

      Normally people define fast and slow relative to the topic at hand. Compared to Hard Drives Random Reads and Writes are magnitudes faster on an SSD.
      LeftSid3
  • RE: Hybrid drives in your future?

    "And keep your standard warranty"

    Lengthen the standard warranty and maybe it'll be worth taking a chance on. The warranty puts your money where your mouth is wrt MTBF claims.
    wkulecz
  • Another sort of hybrid

    I already have an answer: install OS and applications on the SSD and create a /WIP folder for work in progress on the same. When I move files from camera, video ... or start a new development project ... into WIP it goes. When the job is finished out to slow storage it goes.

    So if you only need 120GB for OS,APPS and WIP then there is no problem: likely to be so for consumers, even medium power users ... and becoming less so as the cost of SSD's drops.

    The difficulty appears if the cost of SSD for WIP is prohibitive, which it could easily be on a server, when the hybrid drive might be a solution. I can see why 'optimisation of data placement' is tricky - how do you now how much active data I have!

    I can also see Intel's Smart Response technology being useful too. 32GB integrated onto the motherboard makes for a cheap solution upon which any OEM can build without troubling the consumer.
    jacksonjohn
  • RE: Hybrid drives in your future?

    I like the idea.

    I have often complained that I can't buy a small high speed drive for my operating systems (64 GB - 128 GB) for a reasonable price ($10 - $20).
    I could then store all of my audio, video and VMs on a large "slow" drive.

    What about backup software?
    Can ordinary HDD imaging programs cope with Hybrids and/or SSDs?
    lehnerus2000
  • Small town boy writes small town article.

    So considering 4GB is too small, its lucky Seagate did not release it with 8GB.

    Obviously that would be declared too small too. It's already very fast and capacious. 8GB may price it up further.
    albionstreet
  • bucking the commodity yoke

    HDDs are commodities. No one wants to sell a commodity -- there are no margins. So the HDD vendors cook up a new, non-commodity good: the Hybrid. They innovate in the only segment they can. If I'm a big storage vendor -- even one as eager to please as EMC -- this does nothing for me; I already have flash acceleration and mixed SSDs and HDDs in my arrays. So this becomes a niche item for consumers. In the meantime, the software/filesystem/operating system vendors are going to come up with better solutions.
    ahl_