For example, hard drives feature platters that take a fair bit of energy to keep spinning at thousands of rotations per minute. Power consumption is of course a greater concern for mobile applications, but it's become a key metric for desktops, as well. Those spinning platters also introduce a measure of rotational latency that severely impedes seek performance. The drive head can't just go and grab data from a given target; it has to wait for that target to come 'round on the platter. And then there's the not-so-trivial matter of fragility. Hard drives have become considerably more robust over the years, but moving parts are still prone to damage from jostling and other physical abuse.
Solid-state drives (SSDs) aim to solve the problems associated with hard drive mechanics by replacing them with memory chips. On paper, it looks like a great idea. The first batch of SSDs did offer low power consumption and quick seek times without moving parts, however, actual throughput was dismal and capacities were quite limited.
Now a new wave of SSDs is upon us, led into our labs by Super Talent's SATA25. This 2.5" drive packs a stunning 128GB of total capacity and claims sustained read and write speeds of 60MB/s and 40MB/s, respectivelyhuge improvements over previous solid-state drives. But how does it hold up in the wild? We've run the drive through our comprehensive suite of performance, power consumption, and noise level tests to find out.
The big squeeze
Limited storage capacity has always been a problem for solid-state drives, so the SATA25's 128GB capacity makes it rather special. Traditional hard drives still have a significant storage advantagethe latest 2.5" mobile drives are available up to 320GBbut 128GB probably more than enough for most folks. In fact, I'm barely using 128GB on my primary desktop, and most of that space is consumed by junk I could easily live without.
Cramming 32 memory chips into a 2.5" hard drive form factor is no easy task. Super Talent manages to get the job by spreading chips over a pair of PCBs that are stacked on top of each other. This makes the SATA25 a little thicker than typical mobile drives, though.Most mobile drives measure 9.5mm thick, but the 2.5" drive standard also allows for thicknesses of 12.5mm, 17mm, and 19mm. Fortunately, the SATA25 hasn't completely let itself go; at 12.5mm thick, it's at best packing a spare tire. Of course, that spare tire is one that the drive can't suck in to slide into notebooks designed exclusively with 9.5mm drives in mind.
Super Talent is looking into stacking chips on a single PCB to reduce the SATA25's thickness. However, the company is unsure whether it will be able to slim things down enough to reach the next notch in the belt.If you don't fancy squeezing the SATA25 into a notebook, the drive sports a standard Serial ATA interface and will work in regular desktop systems. It also has an "ultra rugged" metal casing that nicely complements the inherent shock tolerance and durability of solid-state drives.
A lack of moving parts makes Flash memory chips much more durable than mechanical hard drives, but longevity can be an issue. The SLC NAND memory used in the SATA25 is typically good for 100,000 write/erase cycles, and Super Talent quotes drive life at greater than 140 years. Of course, like most mobile drives, the SATA25's warranty runs out in three years.
To help extend drive life, the SATA25 employs wear-leveling algorithms that spread write/erase cycles evenly across the disk to ensure frequently changed memory blocks don't fail before their neighbors. There is no limit on read cycles for SLC NAND Flash memory, so wear leveling isn't necessary for frequently read memory blocksjust those that are changed.