Whether you have a Windows- or OS X-based laptop, one glaring flaw in either genre (and in laptops in general) is the capacity of the hard drive. A year ago, it became possible to pump up a desktop computer with a 3TB drive, but your laptop hit a wall at 750GB. And if you are a true media maven, even 750GB could be a bit confining at times for everything you want to store.
Western Digital (WD) is helping to break new ground with its new Scorpio Blue SATA series of 2.5-in. laptop drives by adding two 1TB models: the 9.5mm-high, 5400rpm WD10JPVT and the 12.5mm-high, 5200rpm WD10TPVT. Both models have an 8MB buffer and are 3Gb/s compatible. For this article, I reviewed the shorter 9.5mm WD10JPVT.
(The taller 12.5mm drive won't fit into many laptops but will still do yeoman's duty in server farms where a slower turning drive with more power conservation technology would generate less heat than its 3.5-inch counterpart.)
More storage in less space
Getting 1TB on a 2.5-inch platter wasn't simple. (Interestingly, the claimed formatted capacity of the drive is a little over 1TB -- 1,000.204GB, to be exact -- not the usual 931GB that marks a 1TB device.) WD achieved it by adjusting the areal density (the number of bits per square inch) and adding Advanced Format technology. (For the full explanation, you can check out a PDF of WD's white paper.
I tested the 1TB Scorpio Blue against a Seagate Momentus ST9750420AS, one of Seagate's high-performance drives -- it's a 2.5 inch drive that has a 750GB capacity. It spins at a faster 7400rpm and has a 16MB cache compared to the Scorpio Blue's 5400 rpm and 8MB.
My essential question: Was gaining the extra storage space with the WD drive (which is available for $84 - $108) worth it when comparing the drive to the more commonly available Seagate drive (which can be found for $82 - $89) with less space but better performance specs? I thought the Momentus' faster rotational speed would overwhelm the Scorpio Blue while its larger cache would be able to keep more data ready to be sent across the host controller to the computer and, therefore, the application requesting it.
Things didn't quite work out that way.
Testing
The first benchmark I used was Simpli Software's HD Tach, a general test that exercises multiple aspects of a drive's performance.
The Scorpio Blue (blue line) was marginally faster than the Momentus (red line) in the HD Tach Sequential Read Speed test.
As you can see in the chart above, the performance delta between the two drives was rather close: the Momentus rated a burst speed of 180.7MB/s vs. the Scorpio Blue's 178.2MB/s. In fact, the Scorpio Blue was marginally faster than the Momentus in sequential read despite the difference in RPMs. That's because even though the Scorpio Blue is not spinning as fast as the Momentus, it can sustain higher sequential reads because the data is packed closer together thanks to its higher areal density.
While the Scorpio Blue trailed the Momentus in every other category, it suffered only nominal setbacks, hardly commensurate with its slower rotational speed and smaller buffer; again, thanks to the more tightly packed data.
Testing the drives using ATTO Technology's Disk Benchmark add some additional granularity to the results.
When data packet sizes were low (64K and below), the Scorpio Blue was at a great disadvantage when writing compared to the Momentus. Data packets at or below 8K were written to the Scorpio Blue at a rate of less than 2MB of data per second while the Momentus handled more than 77MB of data per second. However, once the packet size increased beyond 64K, the Scorpio Blue trailed the Momentus only marginally.
Conclusion
Switching to the higher-capacity Scorpio Blue, despite its slower rotational speed, is practically a no-lose situation. Low data-content files that are typically accessed numerous times -- such as, say, bank or credit records -- are at a slight disadvantage but, as can be seen from the test results, the 1TB Scorpio Blue holds its own with the type of large files associated with streaming and other media-based applications. And since the price of the 1TB drive is about the same as a similar 750GB drive, I strongly recommend it.
