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Is There A Solid State Drive In Your Laptop Future?

Solid State Drives (SSDs) are getting a lot of buzz these days, especially on the PC side where SSD's are becoming a storage option for many PC laptops. The only Apple notebook available so far with optional SSD storage is the MacBook Air, which can be had with a last-generation technology 64 GB SSD for only $599 more than the slightly larger capacity 80 GB standard hard drive. However, that may change in a couple of weeks with the expected rollout of a major redesign of the MacBook and MacBook Pro. It will surprise me if there is not an SSD option on the new MacBook Pro at least - probably a 128 GB one.

However I remain not yet convinced that SSDs represent an advance for general-computing laptop users over the tried-and-true electromechanical hard drive, and I'm skeptical about them ever completely displacing the hard drive, at least with the flash memory technology currently available or on the horizon. What may transpire in the future is of course an imponderable,

The marquee SSD benefit, is that while they are (a lot) more expensive than hard drives, SSDs have no moving parts, which can be a particular advantage for mobile computers that may get bumped or even dropped while away from the relative safety of a desk or table top, although the Sudden Motion Sensor technology Apple has used with laptop hard drives for years now somewhat obviates that factor. Other points in the SSD's favor are minimal seek time and latency compared to hard drives thanks to having no moving parts, lower heat generating capacity, completely silent operation, faster startup time and excellent reliability, although not necessarily longer life. Projected estimates for flash memory cell life is a too-vague-to-be-really meaningful 10,000 to 1,000,000 write cycles, but the real-world life expectancy hasn't yet been tallied. Hard drives are routinely capable of a lot more than that, but using a file system that would spread data writes throughout the drive's capacity ("wear leveling"), could help extend SSD service life substantially.

SSD's may or may not reduce power consumption compared with hard drives, but any superiority in that department is not dramatic, and one performance downside is slow write speed compared to read speed, which is especially significant because today's operating systems like OS X are heavy users of virtual memory which involves lots of reads and writes, so the slow write speed of flash RAM is a big drawback in that context.

Also many of today's hard drives have caches or buffers that store data read from the hard drive and pass it along to the computer, but so far SSDs don't, although there would seem to be no technical impediment to read buffers being incorporated in SSDs.

In my estimation, two of the biggest SSD advantages are that with no moving parts, they run cooler and quieter than hard drives, which helps advance my ideal of dead silent computing unsullied by hard drive or cooling fan racket.

SSD technology is improving at a brisk pace, and Intel recently began shipping what are arguably the state of the art in SSDs, The new Intel X18-M and X25-M Mainstream drives are based on multi-level cell (MLC) NAND flash technology. As the model names imply, the X18-M is a 1.8-inch drive (the size used in the MacBook Air) while the X25-M a 2.5-inch drive which is the standard size for notebook drives.

SSDs also remove input/output (I/O) performance bottlenecks associated with hard drives which helps maximize processor efficiency. Intel claims its internal lab tests show that the X18-M and X25M drives increase storage system performance nine times over traditional hard disk drive performance, and Jeremy Brody, HP's global business notebook marketing manager was quoted this week saying that that Intel's new SSDs increase overall system performance by 57%. In a review posted yesterday, Computerworld's Bill O'Brien reports that in testing the Intel 80GB X25 SSD, it was twice as fast as the next fastest SSD tested and also beat the fastest hard disk drive in reads and ties it in writes, so it appears that that SSDs are finally coming into their own - growing faster, more durable and using less power than traditional mechanical hard drives. O'Brien reported that the Intel X25 SSD is one of the fastest drives - solid state or otherwise - he's tested thus far, thanks to Intel's new technology that interleaves NAND flash chips and uses 10 parallel channels and optimized firmware - beating even high-end, 10,000 RPM desktop hard drives in some performance categories, while drawing less power. The X25-M uses a trivial 0.15W when it's powered up and working.

The new Intel drives use the "advanced wear leveling algorithms" mentioned above in the discussion about reliability in order to avoid hammering the same transistors repeatedly which hastens their ultimate day of failure.

However, Intel isn't the only player SSDs, Samsung, which supplies the 64 GB unit currently available in the MacBook Air, has commenced mass production of 128GB solid-state hard drives, and is promising "more attractive pricing."

The new Samsung drives are expected to be available in 1.8-inch and 2.5-inch versions and in 128GB or 64GB raw capacities (with a 256 GB model projected by the end of this year), and are based on the more advanced multi-level cell technology rather than the slower, less energy-efficient single-level cell technology used in the current MacBook Air drives. Samsung's claims that its new 128 MB SSDs will last "approximately 20 times longer than the generally accepted 4-5 year life span of a notebook PC hard drive," which calculates out to 80-100 years, and a projection of an 800 percent ramp-up in sales of SSDs by 2010. The events of the past couple of weeks in the financial markets will negatively impact that prediction, but I'm becoming more convinced that a SSD probably is in my future. I could get along very happily with a 160 GB or 250 GB drive. How about you?


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cmoore@macopinion.com

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