The Seagate Momentus XT is the ideal choice for those who have been searching for a hard drive that offers the performance of a solid state drive without the premium price. With a street price of around at $135 for the 500GB version, the Momentus XT is just a fraction of the cost of an SSD, and delivers more capacity for your dollar.
Compared with conventional hard drives, the Momentus offers a significant boost in performance by incorporating 4GB of flash memory. The new hybrid hard drive has a built-in algorithm that automatically relocates frequently accessed data on the flash memory area, therefore boosting the device's overall performance over time.
Though about 50 percent more expensive than traditional high-speed 2.5-inch hard drives of the same standard and capacity, we found that the Seagate Momentus XT is worth the investment for its added performance.
Design and features
The Momentus XT hard drive looks exactly like a traditional SATA 2.5-incher that you can find inside most laptop computers. The drive is 9.5mm thick, making it suitable for the widest selection of mobile applications.
On the inside, however, the drive is an entirely new beast. It is the first mass production hybrid hard drive that uses both flash memory and the traditional hard-disk platters for its storage. Seagate says that the Momentus XT features an embedded algorithm, called Adaptive Memory technology, that automatically moves frequently used information into the flash memory for faster access.
| Drive type | 2.5-inch hybrid hard drive |
| Connector options | SATA 3Gbps |
| Available capacities | 250GB, 320GB, 500GB, |
| Product dimensions | 9.5mm, 2.5-inch standard |
| Capacity of test unit | 500GB |
| OSes supported | Windows, Mac, Linux |
| Special features | Built-in 4GB of flash memory with Adaptive Memory technology |
| Software included | None |
In our trials, this technology actually worked. For example, it took our test system, which used a Momentus XT as its main hard drive, the third boot time to consistently boot faster than the first time. Other test applications generally show improvement after using them the second time.
The Adaptive Memory technology is a built-in feature of the hard drive, so it works independently from the operating system. There's no driver or software needed to take advantage of this feature.
The Momentus XT supports SATA II (3Gbps). Unfortunately, it doesn't support the newer and faster SATA III (6Gbps). Currently there's no 2.5-inch hard drive that supports this new standard, however.
Apart from the 4GB of flash memory that's nonmovable, the hard drive's platter spins at 7,200rpm; most laptop hard drives spin at 5,400rpm. It also has 32MB of cache memory, which is higher than most drives of its size. It doesn't, however, offer the other benefits of a true SSD, such as durability and saving energy.
The Momentus XT works exactly like any other traditional SATA 2.5-inch hard drive. We tried installing a few different operating systems with it and ran into no problems. The drive will work with any applications where existing traditional hard drives of the same SATA standard are used.
Cost per gigabyte
The Momentus XT is more expensive in terms of dollars per gigabyte compared with other, traditional drives. Compared with SSDs, even those that offer much less storage space, the Momentus XT is truly a bargain: for the 500GB version, you'll have to pay just 27 cents per gigabyte. One of the most affordable SSDs on the market, in terms of cost per gigabyte is the , and it costs almost ten times as much, at $2.57 per gigabyte.
In addition, you won't be able to find an SSD that offers up to 500GB of storage space. And if you could, you probably wouldn't be able to afford it.



















