2.5-inch hard disk drives with a spindle rotation speed of 7200rpm are very specific products in terms of performance and applications. Such models have always been faster than 5400rpm 2.5-inchers but slower than 3.5-inch HDDs. However, the latter point is arguable now because the lower speed of sequential reading and writing of large files is compensated by the lower response time of 2.5-inch HDDs. Why is their response time lower if the spindle rotation speed is the same? Just because their read/write heads move by a smaller distance due to the smaller diameter of the platters (we are talking about averaged distances, of course) and spend less time for that. 7200rpm 2.5-inch drives have always had rather small storage capacities, though. They are inferior to 5400rpm models in this respect because it is harder to ensure correct operation of the heads in maximum-density zones at the higher spindle speed. So, while the engineers have been solving the problem of interaction between the heads and platters in 7200rpm HDDs on the transition from 100GB to 160GB platters, 5400rpm drives have already switched to 250GB platters, increasing both capacity and speed. As a result, 7200rpm 2.5-inch HDDs do not look superior to their 5400rpm counterparts in terms of speed anymore.
The scope of applications for 2.5-inch 7200rpm drives is not wide but stable. Combining small dimensions, reasonable power consumption and good performance, these HDDs have a guaranteed place in top-performance notebooks such as desktop replacements with large (17 inch and more) displays, top-class processors and graphics cards. These products are going to have the best disk subsystem available, especially as the increased cost of the disk wouldn’t matter much in the total cost of the system. For simpler notebooks users may want to prefer 5400rpm drives which are cheaper and more economical.
Another application for 7200rpm 2.5-inchers is in compact servers that need multi-disk arrays. Again, the low power consumption, high performance, low response time and compact size are all serious advantages of such HDDs for this application. And finally, they can also be installed into small and low-noise desktop PCs. Like all 2.5-inchers, 7200rpm drives are far quieter than their 3.5-inch counterparts.
Unfortunately, such HDDs are not widely available. They do not enjoy high demand among retail customers, and most of them go directly to notebook and server makers. The bad practice of paper announcements should be mentioned, too. Press releases and announcements at the developers’ websites are often posted long before the actual release of a HDD model.