Why SSDs won't replace disks

Why SSDs won't replace disks

Summary: It's simple: we don't produce enough flash to replace more than a few percent of today's disk capacity. But drive vendors would be foolish to take comfort in that fact. They are still in a world of hurt.


It's simple: we don't produce enough flash to replace more than a small percentage of the capacity that disks provide today. But drive vendors would be foolish to take comfort in that fact. They are still in a world of hurt.

In a recent paper titled NAND: can meet the growing storage capacity demands of the laptop PC market?” (pdf) Seagate, soon to be the world's second-largest drive manufacturer, points out that the market for laptop PC disk drives worldwide is 69 exabytes (EB) and is forecast to grow to 95 EB in 2011.

But last year, the flash industry only produced 11 EB of capacity. And 90% of that went into consumer devices such as smart phones, ST cards and drives. It costs over $2 billion to build an exabyte of flash production capacity.

That means an investment of about $200 billion in megafabs to build enough flash to satisfy this year's market demand. Even if equipment vendors could build the fab lines, no one in today's world would finance it. It isn't going to happen.

So what will happen?

Two things:

  • As the advantages of flash-based notebooks and tablets become more obvious to notebook consumers, people will start asking themselves how much storage they really need.
  • SSD-based notebooks will take over the higher end of the market, where the margins are better and average sale prices higher.

This is the problem for disk drive vendors. Sure, people will keep buying low-end notebooks with disks. But the already brutal price competition will get worse and already thin margins will get thinner.

The Storage Bits take The main reason Seagate wrote the paper is to pimp their clever Momentus XT hybrid drives. Since we can't all have SSDs, hybrids may be the next best thing.

Seagate has a point: most of the data on consumer machines - most of the world's data on any machine - is rarely accessed. Why keep it on the most expensive storage if we don't have to?

But the larger point is worth repeating: flash SSDs won't replace disks because we can't build enough flash to do it - even if we were willing to pay the price. And the drive industry is far from done reducing storage costs, so they remain a fast moving target for every non-volatile memory technology.

Which is good news for the data hoarding masses.

Comments welcome, of course. Seagate sent me an XT to review and I found it a worthy effort for the reduced boot times alone. But I hope they are busy tuning their algorithms and doubling their flash capacity to improve performance over a broader range of tasks.

Topics: Hardware, Laptops, Mobility, Storage

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.


Log in or register to join the discussion
  • RE: Why SSD's won't replace disks

    i've heard nothing but problems from Seagate's Hybrid drives - i hope they are planning to start making higher-quality products if they're "pimping" them as the next revolution in storage.

    i do agree w/ your point, though. in fact i think you'll find most SSD power users configure a machine to be almost exactly this; an SSD for boot & common programs, and an HDD for data files & lesser-used programs. I know that's what I'm doing on my home PC and it's working out great.
    • RE: Why SSD's won't replace disks


      I am doing the exact same thing and it is working out great.
  • RE: Why SSD's won't replace disks

    Will operating systems and file systems become smart enough to put commonly access files on an SSD and other files on a standard magnetic HD? Seems like SSD is important for speed of frequently accessed files.
    • RE: Why SSD's won't replace disks

      @lundp@... That's what the hybrid SDD/HDD does. At first boot, you won't notice much of a change, but after each subsequent boot, it learns which files are most often used and moves them to the SSD portion of the HDD.
    • RE: Why SSD's won't replace disks

      @lundp@... Also important for reliability. A SSD will take much more of a beating then a standard HDD.
  • Perhaps true for today's technology.

    Ten years ago I would never have thought I could put an entire music collection on a matchbook sized device (iPod Shuffle). Nor did I think I would be able to afford a solid state drive (even though they are more expensive per GB than traditional hard disks).

    As time marches on so does technology. I can see a time when SSD capacity is sufficient for average needs. Just as todays processors have more processing power for the average user so will SSDs.

    I'm even going to go as far to say I can see the concept of a hard disk disappearing. Instead memory will be composed of RAM and SSD (or just a single memory that combines the speed and accessibility of RAM with the non-volatility of SSDs) and the computer merely accessing everything under a single memory model. No more moving files from non-volatile to volatile memory. No more installing programs...just copy and go.
    • RE: Why SSD's won't replace disks


      I have to agree with you on the ability of SSDs replacing hard drives. It wasn't too long ago when I never thought I would fill a 6GB hard drive, now my OS is larger than that.

      Fact is we have an entire silicon valley, tons of sand to make transistors. the cost of SSDs will decrease in the future, when this does hard drives will become obsolete as by that time SSDs will also be reliable. I remember when I was told never to put anything on a flash drive for long because the drives were unreliable, now they are far better, SSDs will get this way too and then HDDs will be yesterday's news, just like the floppy disk is today.
  • Do What I Did - SSD to boot, External Magnetic Storage for storage

    I have an 80 GB boot drive which I use for the OS and applications. I store everything else on an external drive via eSATA. If I lose the boot drive, no problem, I just reinstall the OS and applications. I don't even back that up. And the external eSATA is simple to back up - just xcopy it to a similar drive and you have a 100% perfect backup. I am convinced this is the way to do it. You have to make sure your important files end up on the hard disc, though. Some applications will put them on the boot partition by default and you have to work around that. If you care about your web favorites, you will probably have copy that to your SSD drive as that will be in the user's folder on the boot drive.
    • RE: Why SSD's won't replace disks

      @goingbust Thank you for your opinion. I really appreciate what you said there. It made the topic more clearer to understand. <a href="http://www.myfbcheatsheet.com/empires-and-allies-hack-download/">empires and allies hack</a>
  • RE: Why SSD's won't replace disks

    I replaced the stock HDD in my ASUS UL with an OCZ 120.<br>For basic data I use 32gb sd cards.<br>I did have to learn to pare down what I thought I really needed.<br>The benefit: longer battery life (from approx 10hrs to 12), quicker boot/load times. <br><br>I may upgrade my ssd or get an external ssd drive but for now the sd and flash drives are working great!.<br>Overall - a win!<br><img border="0" src="http://www.cnet.com/i/mb/emoticons/happy.gif" alt="happy">
    • RE: Why SSD's won't replace disks


      I think that will be that will be a good idea too. will try to use it on my side. <a style="text-decoration: none; color: black;" href="http://www.mayweathervsortiz.org/">mayweather vs ortiz live streaming</a><a style="text-decoration: none; color: black;" href="http://www.mayweathervsortiz.org/2011/07/mayweather-vs-ortiz-tickets.html">mayweather vs ortiz tickets</a>
  • RE: Why SSD's won't replace disks

    Robin; Your readers appear to be overwhelmingly persuaded that SSDs are better deployed as a logical unit of "cache" memory instead of as a replacement for HDD. However, your readers are storage savvy for the most part and I am not convinced that the hype isn't winning the attention of many less informed users. Incidentally, you left out an important pronoun in the title of the paper you referenced and linked. It should read: "NAND: can <i>it</i> meet the growing storage capacity demands of the laptop PC market? The answer, in my opinion is decidedly no. Should NAND be a part of a laptop's hierarchical storage? To me the answer is simply yes. However, the physical packaging and the cost differential will continue to weigh as to how soon that might happen.
    • RE: Why SSD's won't replace disks

      Good points. Seagate realizes that negative hype around disks will impact them and the paper is a solid effort to change the debate.

      IMHO, their bigger problem is that the hype around flash is secondary to the fact that consumer spending growth has moved to mobile devices where disks are not an option or are easily replaced by smaller and higher cost SSDs.

      One of the (fallacious) arguments against the hybrid drive is that when the flash wears out, you throw out the drive. That argument makes more sense applied to mobo flash, since a hybrid disk will still work without its flash, but a mobo?
      R Harris
  • RE: Why SSD's won't replace disks

    Yes they will. Wrong as usual.
    • RE: Why SSD's won't replace disks

      OK, I'll bite. How?
      Robin Harris
      • RE: Why SSD's won't replace disks

        @Robin Harris
        You're 50% correct. NAND FLASH will never replace magnetic storage. It's too expensive to create, not scalable enough, and has other drawback. What will replace magnetic storage is FLASHes successor, be it CBRAM or whatever competing technology will make it to market. A very loose unscientific guess of when we will see that probably won't be till 2015 or later
  • RE: Why SSD's won't replace disks

    They are too small for my own personal taste. But then again, they might just be the right size for other people. <a href="http://www.lane6fitness.com/muscle-maximizer-review/">Muscle Maximizer</a>