Solid state drives (SSDs) have been “next year’s great technology” for about six years now. Each year it seems that all it would take would be some economies of scale, and we could cast off the shackles of mechanical “spinning disk” technology for good. Unfortunately, another year has come and gone, and still SSDs are too little for too much…
The only places you’ll find SSD drives today are in high-end “boutique” workstations for gamers and their ilk, a few over-priced laptops, and on some ultra-high performance server storage farms. When confronted with the difference in price versus the supposed benefits of solid state technology, the average consumer will almost invariably reject the SSD option.
So just how big is the difference in price between and SSD and a traditional hard drive? It varies from month to month, but here are today’s numbers. I can buy a moderate performance traditional hard drive of 1 terabyte capacity for about $100. That works out to about $0.10 per gigabyte. A low end SSD will cost about $400 for 128 GB, and about $750 for 256 GB: call it about $3 per gigabyte, or about thirty times as expensive as a spinning disk hard drive per gigabyte.
What do you get for thirty times the money? Unfortunately, no where near thirty times the value. In most real-world circumstances running a real-world OS doing typical things, an SSD will deliver barely two times the performance of a low end spinning disk. Many users would really only notice faster boot times: day to day tasks will “seem” about the same. The promise of reduced energy consumption is just that: a promise, not a reality. Most solid state drives today are consuming almost exactly the same amount of power as a traditional hard drive, and some would say even more . This is partly because SSDs have to be supplied power all the time, and mechanical drives can be partially or fully powered off when not in use. And there is no appreciable lifespan benefit to SSDs either: they “wear out” differently than a mechanical hard drive, and are much more shock resistant, but they don’t last longer. In some cases, they wear out faster.
To a consumer, there is no real upside to SSDs. They aren’t much faster, they don’t extend laptop battery life, and they don’t last longer. All for nearly thirty times the price: you can see why they aren’t exactly flying off shelves or gaining massive market share. In limited areas, however, SSDs can be very valuable: for certain types of data access they can be dozens of times faster than a mechanical drive, and so you’ll find them in high end (megabuck) storage arrays. In laptops or netbooks, even small shock/heat/weight/power consumption factors can be key: there also SSDs can have some value.
But unless the cost per gigabyte for SSDs drop, they will forever remain a niche product. The problem is that the material scientists and physicists working on mechanical hard drives are just too damn good. And the companies manufacturing spinning disk hard drives have gotten extremely good at efficiency and economies of scale. Today’s best SSD is nearly on par with hard drives… from four or five years ago. SSDs are getting cheaper and more capacious, but at a snail’s pace compared to mechanical drives: the cost per gigabyte for SSDs has dropped by perhaps 10% in twelve months, whereas mechanical drive cost per GB is down about 50% in the same timespan.
Even if something phenomenal happened, like SSDs dropping in price by 50% tomorrow, would that really make a sufficient difference? Certainly for some niche users like myself: I’d buy another SSD if the price dropped by half. But for the average user isn’t likely to spend $100 for a 128 GB SSD when they can get 1000 GB with a mechanical drive for the same price. It would take much more significant performance benefits than are currently observed to tip the scales.
Where will this likely end up? A couple of years ago, I figured SSDs would start to make massive leaps in cost and capacity, but it has not happened. I bought a drive a year ago, and found that the performance benefits were massively over-hyped, so even as a high-end user I’m pretty skeptical of the value. My current theory is that the existing SSD technologies simply are not up to the task. Something completely new is required: it might be a solid state drive (i.e.: no mechanical parts), but it won’t be based on “flash” memory. And, since appropriate alternative technologies are not even visible on the horizon, I expect it will be five or six years at least before we see a significant displacement of mechanical drives for personal computers.