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So with the growth of convergence and cloud storage, will the hard drive, or any of today's other common storage technologies, disappear from the corporate data center?
No. While it would be nice to get rid of every hard drive as a way to improve the management of storage, it will not happen in the coming decade. Individual desktops and mobile PCs will likely continue to use hard drives as their primary local storage, even if customers add SSDs or a flash memory cache to increase performance. And one or more storage appliances will remain on-site with a copy of a business' data for staging latency-constrained backups and for fast recovery of lost or corrupt data.
It's like the tape drive. Forty years ago, tape was dead, said HDS' Basilio. "And yet we're still using it," he said. "Disk will follow a similar path."
People want to get off disks because the power and space they need are costly, Basilio said. "But disk drives remain cost-effective," he said. "Despite falling flash drive prices, they are still much higher than disk prices."
There are a couple areas where hard drive technology is evolving. The first is capacity, or how much data can be stored on an individual drive, which can be impacted in a couple of ways.
The first is areal density, or the number of bits of data that can be stored per square inch on the spinning platters. Average areal density in 2011 was 744 Gbits per square inch, but could grow to 1,800 Gbits per square inch by 2016, according to research firm IHS iSuppli. That would result in capacity-per-drive of 30 TB to 60 TB for 3.5-inch drives, and 10 TB to 20 TB for 2.5-inch drives, compared to a 4-TB maximum capacity this year.
The second measure of capacity is the maximum number of platters that can safely spin inside a disk, which is currently five. That limit stems from the drag caused at the edge of a disk spinning at high speeds, which causes the drives to use more power to spin the disks and requires a certain space between the disks to account for vibrations in the heads and disks from the turbulence. This issue is being addressed with moves to replace air inside the drives with helium, which significantly reduces the friction that causes turbulence and could allow seven or more platters to spin in the same space.
However, don't expect hard drives to get any faster. If anything, they will get slower. The speed at which platters inside the disk spin, as measured by revolutions per minute, is currently at a maximum of 15,000 rpm. But the amount of power needed to push that speed higher is such that drives with higher spin rates are not expected to be offered commercially.
In fact, don't be surprised if 15,000-rpm hard drives get phased out over the course of the next two years. The development of flash-based storage technology will take a bite out of the need for faster hard drives, as even a small amount of flash storage when tied to large amounts of disk capacity results in a significant increase in storage performance.