2.5-Inch Hard Drives Roundup

160 GB 2.5" Perpendicular Magnetic Recording hard drives
versus older 7200 rpm models

Performance of mobile platforms is rapidly growing - there appear new processors and chipsets, system memory clock grows, families of graphics cards are updated, even wireless data transfer speed is increased from 11 Mbps through 54 to 300 Mbps. And only hard drives for notebooks are developing extensively, they are slowly growing mostly their capacity, and do not accelerate much.

Indeed, the average random access time of mobile storage drives has settled long ago. It does not change from generation to generation - spindle rotational speed stays in this segment at 5400 rpm. And only rare 7200 rpm models from IBM/Hitachi and Seagate tried to break this tradition. But they were not successful, because 1.5 milliseconds of difference in the average access rate (owing to the lower rotation latency) do not make any difference compared to much higher absolute results (15-17 ms). Besides, even though mobile 7k1 hard drives outperformed 5k4 models of the same generation in linear transfer rates by 10-20% (which is evidently smaller than the difference in spindle rotational speed), their advantage in real applications was even smaller.

We can see a break-through only with the launch of Hitachi Travelstar 7K100. But at the same time, there appeared the first mobile 5K4 hard drives with perpendicular magnetic recording (PMR). They didn't make a revolution in speed (and capacity), but they still outperformed their predecessors by 10%-20%.

So, there are two leading types of storage drives on the market of notebooks and other devices with 2.5-inch hard drives: 100 GB 7k1 models (see the review above) and 5k4 drives with PMR, up to 160 GB. Several manufacturers announced new models of higher capacity. And we are expecting some of them in our testlab. And if you are interested in maximum HDD performance, so that your HDD system is not a bottleneck, you should pay attention to these very hard drives. This roundup will compare modern 160 GB PMR 5k4 models and 100 GB 7k1 drives from Hitachi, Samsung, Seagate, and Western Digital. We'll do it on the eve of their successors, 250 GB models with PMR of the second generation. Detailed reviews of each of these PMR products are available on our web site:

This article will analyze all of them plus another model - Seagate Momentus 5400.3 SATA. It appeared a lad later than its UATA modification, demonstrating higher performance.

And one more thing. As we examined PMR 5k4 models from various manufacturers, we always came to the same conclusion - delays with the first PMR models (Hitachi relative to Seagate, Samsung relative to the first two models, etc) always did good to the products. Each time the new product was a tad better than its competitors of the same class in terms of performance in typical notebook tasks. The reason was not in technical characteristics in official specifications (they are identical almost in all representatives of this class, see Table 1), but in real parameters we measured in tests and applications.

Table 1. Main characteristics of 2.5-inch hard drives of the first PMR-generation with the spindle rotational speed of 5400 rpm.

We shall skip the analysis of their specifications (you can do it yourself with our table) and their technologies (for example, a head parking technology that guarantees 600 000 Load/Unload cycles), and proceed straight to our tests.