Besides being much slower and more fragile than flash storage, another drawback of disk technology is its physical size. These spinning platters make for cumbersome units. Since the rise of the SSD in its now-popular 7mm form, we’ve seen internal notebook hard disks slim down to match, reducing in thickness from 9.5mm to 7mm. Now Seagate has closed the gap again by introducing the Seven, a complete portable hard drive that is itself just 7mm thick. See also: best portable hard drives 2015 UK. While it’s relatively easy to find a 2.5in SATA disk of 7mm thickness, by the time it’s slotted into an enclosure the overall size tends to swell to more like 11mm. It’s not clear how Seagate has built this portable drive, but we’d guess it’s a single-platter mechanism which expands the raw airtight disk case into becoming the entire drive case. The portable hard drive is made from tough stainless steel with a basic, industrial matt finish. The sides are slimmed down as if the entire unit was stamped and sealed on the production line. In short, this is geek-chic, a tough lump of metal with just a Micro-USB 3.0 port on one crimped edge. And yes, our calipers indicated the Seagate Seven is within a few hundreths of a millimetre of being exactly 7mm thick. See our group test: What’s the best SSD? While the metalwork is specified as stainless steel, meaning we should be assured that it will not rust, it actually proved far from unstainable. Fingerprints from casual handling tended to leave their mark quite literally all over the Seagate Seven’s casework. Special mention must go to the cable supplied with this portable hard drive, a 46cm-long USB 3.0 cable in black that has been finished with a nylon braid. Like that issued with stablemate LaCie’s Mirror, this woven fabric jacket lends a feel of quality to what is otherwise typically an afterthought thrown into the box.
Seagate Seven 500GB review: Performance
With so little space to work with, Seagate could build a hard disk with only a single platter; most laptop disks use two or even three platters. Single-platter technology can sometimes undermine performance slightly, especially under multiple data access conditions that you might need on a computer boot drive. In our tests with Windows 8.1 we saw maximum sequential write speeds from the Seagate Seven at just 49MB/s, although with Windows 7 this was restored to a more typical figure of 101MB/s. Along with the 102MB/s sequential read speed, the Seven proved to be the slowest of all the portable hard drives we’ve tested this month. Tests in OS X also returned the lowest figures, of 98- and 95MB/s respectively for sequential reads and writes. Small files transfer performance reversed this trend, with the Seagate Seven turning in some of the best figures. While 4kB random reads languished at around 0.5MB/s, typical for such disks, the 4kB random writes was around three times faster than most of the competition, if still only at 0.75MB/s. Nevertheless, this all bodes well for speeding up many daily tasks involving small data files. In OS X the Seagate Seven also worked better than most with small data, averaging 15.3MB/s for random small-file reads and a class-leading 14.8MB/s for random writes (averaged with data 4kB to 1024kB).
