Jack Weilandt, chief technologist and director of NStar Electric & Gas Corporation, sees an 8 percent to 12 percent increase in battery life as "marginal at best" and adds that faster boot times are mitigated by the fact that "more boot time is spent in authentication and managed desktop component loads than in the loading of Windows itself." But he says the durability of hybrid drives is attractive. "The key feature to me is that the heads can stay locked for large amounts of time. We put laptops in trucks and carry them to work sites where they can get banged around, so this technology would greatly reduce drive fatalities," he says, adding that a solid-state disk would be even better.
Performance benefits may be the main reason for using hybrid disks in desktops, but Panabaker says some corporate customers have told Microsoft that they'd like to have hybrid drives in desktops so the disk drives will spin down during periods of inactivity, cutting power consumption and heat generation.
The same power savings could benefit servers with direct-attached storage, says Panabaker. And it's likely that ReadyDrive will be integrated into the next version of Windows Server -- though Panabaker won't confirm it. "The code is part of the core bits in Windows," he acknowledges.
The outlook for hybrid disk in networked storage is less clear. ReadyDrive currently doesn't support iSCSI network-attached storage (NAS), but Panabaker says he sees value in supporting it as a way for network storage devices to save power and generate less waste heat in data centers.
Chris Bennett, vice president of core systems at Network Appliance, says he thinks the technology might find a niche in small NAS systems, but he sees "no apparent benefit" for enterprise-class systems, noting that NetApp disk arrays already use faster dynamic RAM caches and are not typically powered down.
However, allowing drives to spin down during periods of inactivity could help data centers face heat and power challenges. "In a server environment, power consumption is a big factor," says Rao. "If you can keep disk drives spun down, that saves power."
Falling prices for flash could make it more attractive for network storage, says Panabaker. Flash "is now cheaper than DRAM, so we see an interesting trend where it may be cheaper in really specialized products, such as some high-end SCSI arrays, to use flash," he says.
As performance continues to climb and costs drop, flash is likely to become attractive for more and more applications. Says Rao, "Anyplace there is a gap between processor performance and disk I/O, flash will apply."
Falling prices for nonvolatile flash memory have prompted some notebook manufacturers to go beyond hybrid disks and announce systems that replace the entire hard disk with a solid-state disk (SSD). In June, Samsung Electronics Co. introduced two notebooks for the Korean market -- the Samsung Q1 and Q30 -- that use a 32GB flash-based SSD that looks like a standard 1.5-in. ATA hard disk drive. In July, Sony launched the Vaio UX90 micronotebook, which includes a 16GB SSD, for sale in Japan and China.
Compared with units with hard drives, SSD-outfitted notebooks boot up and run faster, are quieter and use less power. Samsung claims that its units will boot up 50 percent faster. But they aren't cheap. Sony's UX90, which sells for $US1805, costs $343 more than a unit with a 30GB hard disk. The Samsung notebooks start at $2430. At current prices, 32GB of flash might add $700 or more to the price of a notebook, says IDC analyst John Rydning.
The price of flash, at about $17.50 per gigabyte, has already dropped below IDC's predictions. However, that pales in comparison to disk drives, which cost as little as 65 cents per gigabyte. Disk drives also enjoy economies of scale -- their cost per gigabyte decreases as capacity increases. In contrast, flash pricing tends to be linear. The crossover point for SSD versus traditional hard drives is 10GB, says IDC analyst Dave Reinsel. At capacities above that, hard drives are cheaper.
Today, flash SSDs make the most sense in rugged notebooks for military or industrial use. That's the case at NStar. "The hybrid disk-drive technology is somewhat attractive to us, but I believe that the flash-only drives will be a much better model for us in the future when the pricing of high-capacity flash gets more into the range of commodity pricing," says Jack Weilandt, the energy firm's chief technologist.
Costs will have to come down further and SSD capacity will need to expand before flash SSDs are viable in broader applications, says Rydning. He notes that while the disk footprint for Windows XP is 1.5GB, Vista is expected to come in at between 5GB and 15GB. "That eats up a pretty big chunk of the solid-state disk," he says. Weilandt is less worried. "For many applications, 32GB is more than sufficient for business use," he says.
Given the predicted declines in flash pricing, Don Barnetson, director of flash marketing at Samsung Semiconductor, thinks general-purpose notebooks with SSDs might not be too far off. "I think you'll see [some systems] this year," he says. "But it will go into the mainstream in three to five years."