Seagate Momentus XT: Hyrbid Hard Disk in the World of Cheaper SSDs

In May 2010 Seagate released it's line of Momentus XT Hybrid HDDs which combine a  7200rpm contemporary platter drive with 4GB of SLC NAND memory. The drive incorporates proprietary firmware which automatically and intelligently moves frequently used blocks from the hard drive to the solid state memory for faster access. 

After nearly a year in the market, this Seagate drive remains a popular choice among budget-conscious enthusiasts. In response to comments and criticism on its support forum, Seagate has demonstrated its commitment to the product by releasing not one, not two, but three firmware updates over the course of 11 months. 

But the market has not stood still. True solid state drives have gotten cheaper and cheaper, and the recent introduction of 25nm NAND is set to drive prices down even further. Prospective owners may find themselves wondering how the Seagate Momentus XT fares almost a year on, in the world of cheap(er) SSDs. 

Despite recent developments in the SSD world, the Momentus XT is still significantly cheaper than budget SSDs, and only a few dollars more expensive than top-end 2.5" notebook hard drives. 

The table below illustrates the price point of the Momentus XT. Note that the comparison is against SSDs of a modest 'mainstream' capacity of 120GB - at the time of writing, 500GB+ SSDs still have a four-figure price tag. 

The Momentus XT is no slouch in performance. Nonetheless, do not expect speeds midway between traditional hard disks and solid state drives. Although marketed as a 'hybrid' HDD, the Momentus XT is best seen as a high performance 2.5" notebook hard disk instead. 

The drive performs similarly to the conventional Western Digital Scorpio Black, though it bests the latter in certain very specific usage scenarios. Random access has always been the bane of platter drives, in no small part due to seek time, and in this respect the Momentus XT pulls ahead. However, the comparatively small amount of SLC NAND (4GB) on the Momentus XT means that only frequently used files get to benefit from the instantaneous access time of flash memory. 

In practice, the Momentus XT makes booting and launching frequently used programs such as your browser, word processor and email client very fluid, though in all other aspects it performs very similarly to a conventional high speed platter drive. Statistically, the difference is small. In terms of usability however, the Momentus XT can make your computer feel more responsive. 

The design of the Momentus XT levels the playing field (in terms of performance) with conventional 3.5" desktop hard drives. It is still however, far out of the league of even budget solid state drives such as the previous-generation Intel X25-M. 

Admittedly, the Momentus XT did have some issues at launch time.

Being almost a year old at the time of writing, the drive is now a relatively mature product with a strong community. Over the past year, Seagate has released three firmware (SD23, SD24 and SD25) addressing many of the issues raised by its customers, and has demonstrated its support for the product line. 

While not as speedy as contemporary solid state drives, the Momentus XT could appeal to users who are not willing to pay that extra cash for a solid state drive, but still want to have a small edge over conventional notebook hard drives.

At least outside Singapore, the Momentus XT is positioned at a price point which cannot be ignored. Within Singapore however, potential buyers should carefully consider the value proposition of a previous-generation budget SSD, which is not that much more expensive.