This article can also be found in the Premium Editorial Download "Storage magazine: R.I.P. RAID?."
Download it now to read this article plus other related content.
How much capacity can be squeezed onto a 3.5-inch platter using current technologies? "I expect 8 TB within four to five years," predicts Greg Schulz, founder and senior analyst at StorageIO Group in Stillwater, Minn. With new materials and different technologies, Schulz won't be surprised to see HDD capacity continue to increase dramatically. Jon Toigo, CEO and managing principal at Toigo Partners International, reports a Toshiba breakthrough that stores 4 TB per square inch (not per 3.5-inch platter). Toigo predicts a 4 TB/sq. in. disk drive within 36 months. Similar advances and new materials promise equally dramatic increases in tape capacities.
A general cost per gigabyte of HDD storage is difficult to pin down due to the wide variety of HDDs with different capacities and speeds, and the different ways HDDs are packaged and sold. Still, there are ballpark approximations. For example, a high-performance FC drive in an array would run approximately $80/GB; stick it in a SAN and the cost bumps up to $180/GB, according to Toigo. Figure approximately $60/GB for a SAS drive in an array and $160/GB in a SAN; SATA drives are about $40/GB.
Prices are rock-bottom for consumer-quality hard disk drives with some retailers selling 1 TB 5,400 rpm drives with a USB connection for $89 or less -- about 9 cents per gigabyte! These may not be industrial-strength drives, but at that price a manager could buy a handful and back up an entire workgroup or department several
Given the low cost/GB, especially for drives with capacities of 1 TB or more, some storage managers are snapping up the largest drives they can buy. "We're always buying more hard drives. We buy SATA for the low end, SCSI for the midtier and we even have a tiny amount of SSD," said Ben Higginbotham, director of new technology at WhereToLive.com, a Web development firm and SaaS provider for the real estate industry. Most recently the company has been buying 1 TB SATA drives in its ongoing quest for more storage capacity. Next up for the company as it continues to ride the price/capacity curve are 2 TB drives.
Thomas Weisel's Fiore is also constantly seeking greater capacity with both 3.5-inch and 2.5-inch HDDs. "We want to get the most capacity in the smallest footprint. It's a real estate issue with us" he said. Going from 1 TB to 2 TB doubles the amount of capacity for each drive shelf. Similarly, with 2.5-inch HDDs he can pack more drives into the same space.
But not every storage manager is enamored with the biggest drives. "The cost per gigabyte is appealing, but the 1 TB and 2 TB drives also scare me because of the increased risk of failure," said Darrell Stymiest, director of IT operations at UGL Unicco, a facilities services company based in Newton, Mass. Instead, Stymiest prefers to buy smaller drives, currently 300 GB or 500 GB capacities.
Form-factor and interface changes
The greatest capacities are still in the 3.5-inch HDD form-factor, although there's a gradual transition in enterprise storage to the 2.5-inch HDD, which currently tops out at approximately 600 GB. "The 3.5-inch disk is still a major part of the market," said Teresa Worth, senior marketing product manager at Seagate. "By 2012, 2.5-inch disk will pull even; from then on, 2.5 inch will take over." IDEMA's Geenen concurred: "Enterprise storage today is still 3.5-inch disk, but that's changing to 2.5 inch."
The appeal of the 2.5-inch hard drive technology is energy efficiency. "The 2.5-inch drive offers a 60% improvement in power," Worth said. With vendors like Seagate adding intelligence to the devices that allows storage managers to selectively reduce disk spinning, hard disk drive power consumption can be reduced even more.
This was first published in May 2010