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Seagate Momentus XT (second generation review: Seagate Momentus XT (second generation

Seagate Momentus XT (second generation

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
6 min read

The Seagate Momentus XT (second generation) is a worthy upgrade to the original Momentus XT that was released more than a year ago. The new drive now comes with twice the amount of flash memory (also known as solid-state storage) and offers 50 percent more storage space.

Seagate Momentus XT (second generation, 750GB)

Seagate Momentus XT (second generation

The Good

The <b>Seagate Momentus XT (second generation)</b> offers performance similar to solid-state drives (SSDs) while being much more affordable. The new drive now supports SATA 3 (6Gbps) and provides 750GB of storage space.

The Bad

The new Seagate Momentus XT is noticeably more expensive than regular hard drives of the same storage space. Its data copy speed is comparatively slower than that of high-end hard drives.

The Bottom Line

Similar to the original, the Momentus XT (second generation) makes an excellent host drive for any computer, both laptops and desktops. It offers great value in terms of performance and cost, especially when compared to SDDs.

Performance-wise, the new hybrid drive is almost identical to most SSDs in terms of boot, wake-up time, and application loading. When it comes to copying a large amount of data from one place to another, however, it's just about average among all hard drives. However, the drive isn't designed for data transferring, it's mostly designed to be used as the main drive of a computer that hosts the operating system.

At the suggested price of $250 for 750GB, the new Momentus XT offers an excellent alternative to SSDs.

Design and features

Drive type Internal drive
Connector options SATA 3 (6Gbps), SATA 2, SATA
Available capacities 750GB
Product dimensions 9mm thick, 2.5-inch standard
Capacity of test unit 750GB
OSes supported Windows, Mac, Linux

The new Momentus XT looks exactly the same as the previous version, which is basically like any other standard SATA 2.5-inch internal hard drive. The drive is the standard 9mm thick, so it should fit all storage slots that use 2.5-inch hard drives. In short, just from its looks, nobody can say that it's not a regular hard drive.

On the inside, however, the drive is anything but regular. This is a drive that comes with 8GB of high-speed single-cell flash memory--the type of flash memory used in enterprise-grade SSDs--on top of a regular platter-based storage. (The original Momentus XT comes with only 4GB of flash memory). The resulting combination of the two offers 750GB of hybrid storage and works based on Seagate's Flash Assisted Storage Technology, or FAST. But you don't have to worry about how hybrid storage works; the drive can be used just like any hard drive.

Similar to the previous model, the new Momentus XT also features an embedded algorithm called adaptive memory technology that automatically and independently from the operating system moves frequently used information into the flash memory for faster access. The fact that it now comes with twice the amount of flash means that more data can be moved to this area, making the drive work even more similarly to an SSD.

Unlike that original drive that supports SATA 2 (3Gbps), the new drive now supports SATA 3, which is twice as fast. While its 8GB of flash memory doesn't have any moving parts, the drive's platter-based storage works like that of any other hard drives and spins at 7,200 rpm, which is the spinning speed of high-speed laptop hard drives. This also means that, the drive, similar to any hard drives, is more susceptible to shocks and vibrations than SSDs. It also uses more power and generates more heat than SSDs.

Cost per gigabyte
With a suggested price of $250 for 750GB, the second-gen Momentus XT costs about 33 cents per gigabyte, about 3 cents per gig more expensive than the original Momentus XT. Compared to SSDs, which cost from $1.10 to up to some $3 per gig, it's still much more affordable. Also note that it's currently very hard to find an SSD that's 750GB or larger, even if you can afford it.

Note that the prices shown here are as of the time of this review. Prices of storage devices fluctuate a great deal and tend to get lower over time.

According to Seagate, the Momentus XT's adaptive memory takes time to show improvement in performance, and that was true in my testing.

When I first booted the computer with the new drive, it didn't seem much different from a regular hard drive. However, starting with the second time, the boot time reduced significantly. By the third boot, the drive's boot time was exactly the same as when the test computer used an SSD as its main drive.

This was similar to application launching time. In my testing, there were significant differences between the first and the subsequent launching times. Starcraft 2, which is a rather large game in terms of data, for example, took about 35 seconds to load the first time, down to just 20 seconds, the subsequent times. The wake-up time from sleep mode, however, didn't require any learning. From the very first boot, the computer would wake up almost instantly from standby mode, significantly faster than when the computer uses a hard drive as its main storage.

The process is reversed, too; if you don't use an application for a long time, the first time you run it again, it will take a longer time to start up.

Overall I was happy with how the new drive improved the computer's startup, wake-up, shutdown time, and application performance. Its copy speeds, however, weren't as impressive.

When used as the secondary drive, the new Momentus XT registered about 80MBps when I copied a large amount of data to it. This wasn't slow, but slower than some other high-speed hard drives. The high-end WD VelociRaptor hard drive, which spins at 10,000 rpm, for example, offers around 126MBps.

When used as the main drive of the computer, which is its main purpose, the Momentus XT's copy speed was reduced to just 34MBps. This reduction was expected since the drive had to do both writing and reading at the same time, and again, it was slower than the WD VelociRaptor.

Note that this is not a big deal since I used a huge amount of data, some 55GB, for the copy test which can't all fit on the drive's 8GB of flash memory. This means in copy tests, the new Momentus XT is supposed to perform just like any other 7200rpm laptop hard drive, which it did.

Overall, similar to the original Momentus XT but at a higher level, the second generation drive provides very good improvement to a computer's general performance. While it's not as fast as most SSDs, it offers the overall experience very similar to one, most of the time.

Boot and shutdown times (in seconds)
(Shorter bars indicate better performance)
Boot Time  
WD VelociRapter 300GB
OCZ Agility 3
OCZ Vertex 3
Crucial M4
SanDisk Ultra
Patriot Pyro

Data transfer scores (in MB/s)
(Longer bars indicate better performance)
As secondary drive  
As OS drive  
Samsung 830 Series
Plextor PX-256M2S
OCZ Vertex 3
Crucial M4
OCZ Agility 3
Patriot Pyro
Sandisk Ultra
WD VelociRapter 600GB
Seagate Barracuda XT
WD VelociRapter 300GB

Service and support
As with the original Momentus XT, Seagate backs the Momentus XT (second generation) with a generous five-year warranty. This is the longest warranty you can expect from a storage device, and is also the most important support factor for a hard drive.

With larger storage space and excellent overall performance, the new Momentus XT makes a great replacement drive in any laptop or desktop computer for those who can't afford an SSD. The drive will offer an even better value when its street price gets lower.

Seagate Momentus XT (second generation, 750GB)

Seagate Momentus XT (second generation

Score Breakdown

Design 8Features 8Performance 8Support 9