"Real progress for 2.5 is coming from the enterprise market where many servers have been launched with bays only for these miniature drives. The premise is simple; smaller drives means you can fit more in the same amount of space. When it comes to rack mount servers space comes at a premium and it is sold in 1.75 inch sections. In a typical 1U server where the hard drives are mounted in removable bays, you could fit four 3.5 inch bays. Take that same server and configure it for 2.5 inch drives and you can add an extra row vertically and horizontally to make it a ten drive server.

The Seagate Savvio 15K.2 is a second generation 2.5 inch form factor hard drive that uses the SAS 2.0, 6Gb/s interface. Let’s move on and see how well it fares."