Solid-state storage finds its niche
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With fundamental technology changes in store for HDD as the industry struggles to increase areal density (the amount of data that can be packed onto the disk) beyond what can be achieved with the latest perpendicular disk technology, disk drive vendors find themselves looking at SSD as a potential competitor.
"We've seen a growing focus on flash at HDD companies in the last six to nine months," says Joel Weiss, president, International Disk Drive, Equipment and Materials Association (IDEMA). For example, Seagate Technology LLC, an HDD leader, is already deep into flash and hybrid technologies (see "Hybrid storage," below). As a sign of change, IDEMA has opened its membership to flash manufacturers.
|Hybrid storage combines flash with hard disk drives (HDDs). The first devices add 256MB of flash to a conventional disk drive. "The flash sits between the system's RAM and hard drive," explains Josh Tinker, market development manager, personal computer business unit at Seagate Technology LLC. The benefits of hybrid storage are minimal until Microsoft Windows Vista enters the picture.
"Vista has SuperFetch, which manages the memory architecture to take advantage of the flash,"
| says Tinker. Having 256MB of nonvolatile memory enables a drive manufacturer to do more in terms of energy reduction and reliability. For example, it can stop spinning the disk for periods of time and rely completely on the flash portion, which saves energy and wear and tear on the drive.
At this point, Seagate's hybrid drive will show up first in high-end laptops (running Vista), where conserving battery is a big concern. However, it demonstrates what might be done when enterprises combine solid-state disk and HDD storage.
Flash is nonvolatile storage, which means the data remains even if the power cuts out. Everybody has seen flash, especially NAND flash. It's the storage behind Apple's iPod nano and is widely used in portable USB storage devices. Although flash storage comes in NOR and NAND flavors, this article refers only to the NAND version of flash. "When people talk about flash memory today, they are referring to NAND flash," says Krishna Chander, senior analyst, storage systems at iSuppli Corp., a research firm in El Segundo, CA. The terms NOR and NAND refer to the logical electronic gates (OR and AND) that make up the memory chip. NOR means not OR and NAND means not AND.
This was first published in November 2007