You can’t have too much of storage space. Every PC or notebook user is going to tell you that. And while in a desktop PC you can increase the amount of storage by replacing your HDD with one that has a larger capacity or by adding one more HDD into your system, you can only go the former way with your notebook or small form-factor PC. Of course, you can use external HDDs with USB, FireWire or eSATA interfaces but they usually prove to be slower than HDDs connected directly to the mainboard via the already widespread SATA interface. Mobile HDDs may also prove unhandy as they mean one more device with additional weight and volume you have to deal with.

That’s why it was 2.5” HDDs that became the first drives to use perpendicular recording technology. You can refer to one of our earlier reviews for reasons why the manufacturers had to change the direction of recording (and also the material of the platters, the heads, and the electronics), see our article called Seagate Momentus 5400.3 160GB Hard Disk Drive with Perpendicular Recording Technology. The new technology provided the best effect possible for HDDs of this form-factor and all the makers eventually transferred their 2.5” HDD series to perpendicular recording. Increasing the amount of platters (like in 3.5” HDDs that can have up to five platters per drive) is not an answer for a 2.5” drive because you can’t fit a third platter into it without making it thicker. And a thicker drive won’t fit into the standard bay. Although such thick models, mostly from Fujitsu, do emerge on the market, they enjoy but a very limited demand.

So, the choice is made in favor of perpendicular recording. Having overcome the unavoidable technical problems and made contracts with the distributors, the developers all introduced new HDD series reaching a recording density of 80GB per platter in the first generation. By the way, the recently released second-generation models feature a recording density of 250GB per platter but that’s going to be the subject of our upcoming review. Today I’ll discuss six 2.5 HDDs with a capacity of 160GB, a spindle rotation speed of 5400rpm and a SATA interface.