Hitachi: 4-Tbyte Hard Drives Coming
However, solution providers looking for such drives now will be disappointed. They probably won't be available until 2009, and in any case solution providers said the market is still trying to find a use for 1-Tbyte hard drives.
Areal density, a measure of how many bits of data fit a given space on a hard drive platter, has continued to grow even as storage technology developers look for alternatives to spinning disk drives, said John Best, chief technologies to Hitachi GST.
Hitachi has reduced existing hard drive recording heads by more than a factor of two in its new perpendicular-to-the-plane giant magnetoresistive (CPP-GMR) heads, which will enable hard drive recording densities of up to 1 terabit per square inch, compared to its highest areal density in current products of 200 gigabits per square inch.
This results in two possible technology directions for future hard drives, Best said.
The first is the development of high-capacity hard drives, including up to 4 Tbytes per drive in a desktop form factor or 1 Tbyte per drive in a mobile PC form factor, he said. This compares to the existing limit of 1 Tbyte per drive.
"They could be used in HDTV or similar applications where people don't want to erase data," he said. "Applications where performance is not a big deal. Maybe with near-line storage for archiving."
The second direction is smaller, high-performance drives, Best said. Because of the increase in areal density, data is packed closer together, making it possible to read it quicker and increasing the performance of smaller drives, he said.
Solution providers said they see application for new larger capacity hard drives, but not where performance is a concern.
Dan Carson, vice president of marketing and business development at Open Systems Solutions, a Willow Grove, Penn.-based storage solution provider, said he can see applications for 4-Tbyte drives in disk-to-disk backups and disk-based archiving, and other places where performance is not important.
"But the 1-Tbyte drives have not made their way to the enterprise yet," Carson said.
The biggest issue with using terabyte-plus hard drives is the increasingly longer rebuild time needed if a drive in a RAID set crashes and needs to be replaced, Carson said.
"A 300-Gbyte drive already takes hours," he said. "Larger drives add risks, and overall RAID performance falls during the rebuild process. That's why for RAID sets, people prefer smaller hard drives."
David Stone, vice president of business development at Solutions-II, a Littleton, Colo.-based IBM solution provider, said the market has almost never been ready for leading edge technologies like the upcoming hard drives, but that solution providers manage to absorb them anyway.
"The 4-Tbyte or whatever drives will give us new capacities and lower costs," Stone said. "But they will also throw us new problems -- how to back them up, how to protect them -- so we can work with customers on them."
Stone expects the market to use the new areal density technology for smaller, high-performance drives before adopting larger capacity models. "Right now we have a lot of good, high-capacity drives that don't perform like we want them to perform," he said. "If we take what is available now and increase performance, that is what the market wants.
Questions about issues such as the long rebuild time for drives in a RAID set are not new, Stone said. "I've been in this industry since 1983," he said. "We always ask the same questions whenever a new hard drive technology comes out, questions about performance and how long it takes to re-build."
Hitachi also expects the new technology to be adopted in mobile hard drives first, as has been the traditional product road map for Hitachi, including the current perpendicular recording technology, Best said. "But it's hard to predict," he said. "The technology will start to come into play in 2009 or 2010, and by 2011 we may see a 4-Tbyte hard drive," he said.