Hybrid hard disk gets flashy speed boost
May 24, 2010 — by LinuxDevices Staff — from the LinuxDevices Archive — 1 viewsSeagate announced what it's calling the “world's fastest 2.5-inch laptop PC hard drive,” combining 7200rpm rotating platters with 4GB of solid-state memory. The OS-independent Momentus XT boots up to 100 percent faster than traditional laptop drives, but costs much less than SSDs (solid state disks), the company claims.
The new Momentus XT is not Seagate's first hybrid hard drive; The company's 2007 Momentus PSD (PDF datasheet, here) combined a 5400rpm drive and 256MB of flash memory as a cache, but concentrated on power saving rather than performance and required Windows Vista. The new XT, on the other hand, is said to be OS-independent, and combines a 7200rpm rotating drive (in 250GB, 320GB, or 500GB capacities) with 4GB of SLC (single level cell) flash memory.
Seagate's Momentus XT
The Momentus XT (above) also has 32MB of RAM cache, similar to many other hard disk drives, so the flash memory — mounted on the device's controller, as seen at right — adds as a second-level cache. Seagate says its "unique adaptive memory" scheme identifies the most frequently used information, then moves it to flash storage for faster access.
As a review on AnandTech by Anand Lal Shimpi further explains, writes never touch the flash memory directly. Instead, data is only moved to flash over time, as the drive's controller notices the relevant files being accessed frequently.
In Shimpi's testing, a Momentus XT took about 33 seconds to boot Windows 7 for the first time, compared to a Patriot Inferno 100GB SSD (solid state disk), which took only 11 seconds. On a second run, however, the XT was able to achieve an almost 100 percent performance boost, booting the operating system in 15 seconds.
Another interesting test performed by Shimpi involved throwing Internet Explorer, Outlook 2007, Access 2007, Excel 2007, PowerPoint 2007, Word 2007 and Photoshop CS4 all into the startup folder of his testbed machine. When equipped with the Patriot Inferno, the PC loaded all of those apps in 6.3 seconds, but it was able to do so in 8.9 seconds with the Momentus XT — twice as fast as either of the standard hard disk drives that were also tried.
Concluding that the "Momentus XT should become the standard hard drive in any notebook shipped, Shimpi adds that it "isn't quite as fast as an SSD, but is a significant improvement over the mechanical drives found in notebooks today." However, he cautions, an intensive test of random read/write performance gave "abysmal" results — even worse than standard hard drives — and ultimately prevented the device from feeling like an SSD most of the time.
A comparison of the Momentus XT and other drives
Source: Seagate
(click to play)
Availability
Seagate said "channel and OEM shipments" of the Momentus XT have begun, adding that the device will be offered as an upgrade option for the new Republic of Gamers G73Jh notebook from Asus. A demonstration of the XT will be given via a live webcast scheduled for Wednesday, May 26, and three attendees will win a G73 system, according to the company.
To register for Seagate's Momentus XT webcast, go here. For more information on the device, see the company's website, here.
Online retailers such as Amazon and Newegg are accepting orders for the Momentus XT, although none seems to have the drive in stock at the time of writing. While Seagate did not cite pricing, the XT lists for approximately $148 in a 500GB version, $126 in a 320GB version, and $118 in a 250GB version, according to Amazon.
Anand Shimpi's AnandTech review of the Momentus XT may be found here. Other test results may be found on the Channel Register website, here.
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