Despite historical declines in sales last year and the onslaught of solid state drives, hard disk drive shipments are expected to soar through 2014, representing 300,000 petabytes of capacity, according to a new study released by market research firm IDC.

The study, Worldwide Hard Disk Drive 2010-2014 Forecast, estimates that hard disk drive purchases for use in enterprise-class applications will increase by more than 12 million units by 2014, or from 40.5 million in 2009 to 52.6 million.

Additionally, the total amount of capacity on hard drives shipping in the next two years will be more than the amount the industry shipped over the past 20 years, IDC said.

IDC said a growing interest by enterprise-class companies in new storage delivery models, such as storage as a service or in the cloud, will place greater demands on Internet data centers.

The research firm also said the price per gigabyte of performance-optimized HDD storage will continue to decline at a rate of approximately 25% to 30% per year, and that the industry's transition from 3.5-inch to 2.5-inch performance drives will be completed by 2012.

Over the next four years, there will be a shift away from higher cost, performance-optimized hard drives to lower cost, but higher capacity serial ATA (SATA) drives. The performance-optimised drive market is made up of 10,000rpm or 15,000rpm drives with either a Fibre Channel or serial-attached SCSI (SAS) interface. In conjunction with that shift, enterprises will also increase their purchases of solid state drives (SSDs) to deal with the smaller number of applications requiring high I/O throughput, such as video streaming and relational databases, IDC said.

Through 2014, hard drive revenue in the enterprise markets will grow at only a 1.7% compound annual growth rate. Organisations will also continue to optimise their existing infrastructures.

"We're definitely seeing intensive cost cutting measures among end users striving to bring more efficiency to current solutions," John Rydning, IDC's research director for Storage Mechanisms, said in a statement. "The employment of technologies such as data deduplication, thin provisioning, storage multitiering, and storage virtualisation are all contributing to reducing end-user costs."