IHS iSuppli predicts desktops are set to adopt 2.5" HDDs as the All-in-One PC form factor gains favor:
Demand from all-in-one PCs combined with requirements for lower power consumption and a thinner, smaller storage alternative to existing 3.5-inch hard disc drives (HDD) will help create a viable market for 2.5-inch HDDs in desktops beginning next year.

Worldwide shipments of 2.5-inch HDDs to all-in-one PCs are forecast to reach approximately 1 million units in 2013, up from virtually zero this year, according to an IHS iSuppli Storage Space Market Brief from information and analytics provider IHS (NYSE: IHS). Shipments then will increase to 3 million units the following year and rise steadily until they hit some 7 million units in 2016, as shown in the figure below. The HDD market for all-in-one PCs will continue to be dominated by 3.5-inch discs, with shipments by 2016 estimated at 31 million units, but growth will be much slower for the segment during the same period than for 2.5-inch drives.

The 2.5-inch HDD is used widely today in a variety of products, including mobile or notebook PCs, external hard disk drives and in enterprise applications such as servers and storage systems. Their advantages over conventional 3.5-inch HDDs include a smaller form factor, lower power consumption and higher endurance.

Of late, however, the 2.5-inch drives have also become attractive and desirable for desktop PCs, especially among all-in-one computers.