When Seagate first told me about its new line of 2.5-inch Momentus drives I asked for two of them. Being greedy aside, there were two big deals: 500GB, 7200rpm, and an optional G-Force Protection technology.

G-Force: The G-Force Protection feature provides enhanced data protection against shock that may occur while the drive is operating. This feature is designed to decrease the likelihood of data loss by detecting a freefall event and unloading the actuator before a shock takes place in falls of greater than 8 inches (nominal). The drive uses a drop sensor mounted on the printed circuit board assembly to sense this event and protect your data.

Of the two drives I wanted, one was to be an “AS” designation and the other the GeForce version, designated “ASG.” I wanted to know if that sensor sitting on the printed circuit board had any affect on the overall speed of the drive. Seagate sent me an ST9500420AS…

I can point to the economy and any number of other reasons for only receiving the one drive but it’s not the first time I’ve run into such a situation. When Hitachi unleashed its encrypted drive, it couldn’t come up with one for me to test either. Such is life…

Key Advantages

Highest available notebook performance
500-GB capacity
Native Command Queuing
Green features:
Lowest-power 7200-RPM laptop hard drive yet
Ramp load features improve idle power consumption
State-of-the-art error correction
Fluid dynamic bearing motor
Support for S.M.A.R.T. drive monitoring and reporting
Support for Read Multiple and Write Multiple commands

Best-Fit Applications

High-performance and mainstream laptop PCs
Small form factor PCs
Workstations
Industrial applications
Non-mission-critical blade servers

Let me also add that, at 500GB, this is an excellent potential component for a 2 - 5 drive mini-NAS. That capacity has always been big news in this size arena and 7200rpm makes it a desktop competitor –just smaller. (Western Digital, Samsung, and Fujitsu also offer 500GB 2.5-inch drives but they spin at a slower 5400rpm, except for Fujitsu which turns at 4200rpm to keep power requirements as low as possible.)

Performance
SimpliSoftware’s HDTach was used for the initial testing. As well as the Momentus, I also tested a Patriot 128GB Warp SSD and a Western Digital 320GB Scorpio Black 7200rpm drive, which is another mechanical hard disk.

As you might expect, the Warp SSD had the best Average Read speed at 139.5Mbytes/s. The Momentus pulled a 86.4MBytes/s score from HDTach and that may not seem like much in comparison until you get to the Scorpio Black which scored 63.8MBytes/s.

(I don’t usually bother with Burst Speed because its just the transfer rate from the drive to the buffer on the interface card. It might be noteworthy, however, to point out that the Scorpio Black showed a 235.8Mbytes/s burst speed to the Momentus’ 177.1MBytes/s and the Warp’s 173.4MBytes/s.)

There was a surprise waiting for me when I got to some real copy and paste operations. I use a packet of 4,661 files (8.05GB) that consists of folders and files that included video and graphic mpeg, mp3 music, .wav files, and Word, Excel, and .txt files.

Pasting that group of files to the Momentus took 2.6 minutes. That’s 1/10 of a minute slower that the Scorpio Black and nearly a full minute faster than the Warp SSD. Yes, it writes faster than an SSD but most SSDs are porkers when it comes to writing. In contrast, the Warp needed only 118.5 seconds to copy the data and put it back on the drive it originally came from. Here’s the surprise: the Momentus needed only 120.7 seconds –a negligible 2.2 seconds more– to do the same. (The Scorpio Black ran through the task in 136.7 seconds.)

You can see the benchmark numbers here.

Conclusion
I’ve found the ST9500420AS at both Dell and Newegg and each is selling it for $140. It’s out of stock at both places –which may mean something about the drive’s desirability. (“May?” Are you crazy, Bill?) That’s pretty steep when compared to the world of desktop drives but in the notebook world, for the maximum capacity hard drive available, it’s not such a bad thing at all. In fact, it’s only about $40 more than the slower 5400rpm 500GB drives on the market.

At a Glance:
Seagate Momentus 7200.4 ST9500420AS
Seagate
http://www.seagate.com/www/en-us/products/laptops/momentus/momentus_7200.4/
Price: $139.99 (Strreet)

Pros: Fast, 500GB notebook drive at last!
Cons: Can’t mount it in my desktop!!

The Final Nudge: Seagate has done good, real good.