El Segundo, Calif. - All-in-one (AIO) desktop computer hard-disk-drive (HDD) growth area is expected to shift to the smaller 2.5-inch disks, according to IHS iSuppli.

The research firm said the change is due to the growing number of AIO PCs that require a thinner HDD. The AIO HDD market is now and will remain dominated by 3.5-inch drives.

IHS is forecasting 1 million smaller HDDs will ship for AIOs in 2013, up from zero this year. The number will climb steadily, reaching 7 million shipping per year by 2016. However, despite this growth, 2.5-inch shipments will still lag far behind the number of 3.5-inch drives shipping for use in AIOs. IHS expects 24 million 3.5-inch models to ship this year, growing to 31 million in 2016.

Even though 2.5-inch HDD growth will remain much smaller, IHS believes the AIO category gives this drive category new room for growth outside of its traditional space in the laptop and external hard-drive categories.

IHS iSuppli Figure: Worldwide Shipment Forecast for 2.5-Inch and 3.5-Inch Hard Disk Drives to All-in-One PCs (Millions of Units)   2011 2012 2013 2014 2015 2016 2.5" HDD in all-in-one PCs 0 0 1 3 5 7 3.5" HDD in all-in-one PCs 18 24 26 27 28 31 Source: IHS iSuppli Research, April 2012