Solid state storage
Article Date: Jun 10 2009
Storage technology is moving on
Storage technology is far from what most would consider the glamorous end of IT. But if you've bought a laptop recently, you may have noticed a new option being offered to you when you select a hard drive.
SSD, or Solid State Drives, represent a new twist on an old idea: flash-based memory. ‘It’s the same stuff you have in SD cards, cameras and iPods,’ says Nick Baker, storage guru at Sun Microsystems. ‘It’s one of the most exciting things that’s happened in storage in years,’ he adds.
Whether or not you share the excitement, SSD certainly promises to have a major impact on the computer industry. Processors and graphics chips have progressed to such an extent that the hard drive is now often the slowest element in the machine; the fastest hard drive is typically 260 times slower than a modern CPU, and a major performance bottleneck.
The basic design, as Baker puts it, has also changed little in 30 years, and because of the number of moving parts represents the major point of failure in any PC or laptop.
When you drop a laptop, it’s the hard drive that usually breaks. They are responsible for a significant part of a computer’s power footprint at about 15-20 watts, and when a chassis fan gets clogged with dust, it’s the hard drive that overheats and cracks: ‘You can track the number of hard drives failing directly to air conditioning fluctuations,’ says Baker.
In comparison, flash-based solid state storage devices have no moving parts, are far more reliable and durable, can withstand extreme temperatures, run on as little as 2.5 watts, produce no heat or noise, and read data at up to 100 times the speed of a conventional hard drive. To compete, a hard drive would have to spin at 200,000rpm, or several times the speed of sound.
That makes SSD ideal for laptops and portable devices, and any application where performance is desired over capacity; while the cost is coming down, it averages £23 a gigabyte compared to £3 for a normal hard drive. Apart from the extra cost, SSD suffers from poor-to-average performance when writing data to your device (as opposed to reading from it) although certain hybrid models under development are addressing this. Like USB devices, they have a limited number of “write cycles” giving them a limited, but predictable, shelf-life of three to ten years depending on quality.
Right now SSD is an affordable and highly desirable luxury for any laptop device not being used to store large amounts of data, such as photos (and even then, you can use a cheaper portable hard drive). More innovative uses of SSD include applications such as transactional databases, or anything else that is accessed frequently such as video-on-demand. They also have cost-saving potential in the data centre, where heat management is a major operating expense. But thanks to the low write speed, you won’t be using them for backup any time soon.
