Samsung specializes in NAND, and other companies are also seeing the benefits of this type of flash. On November 21, Intel and Micron Technology Inc. announced the formation of a spin-off company to manufacture NAND flash memory.
“In 2006, flash will start to penetrate the PC,” says Barnetson. Microsoft’s next-generation operating system, Vista, is designed to run best on PCs that include 128 megabytes of flash memory in addition to a traditional magnetic hard disk.
This “hybrid drive” will produce a number of noticeable benefits, says Barnetson. For one, information can be written to the flash drive, and then, about every 10 minutes, dumped from flash memory to the hard disk. This means the hard disk spins only periodically, reducing the amount of power consumed by 90 percent, according to Barnetson. And since a hard disk chews up about 10 percent of a computer’s power, this could translate into 30 more minutes on a laptop’s battery charge.
Moreover, because flash is “nonvolatile,” meaning it stores data even when the power is off, the flash memory in a computer can act as a backup, keeping files intact. Storage without power will also enable these hybrid machines to start up almost instantly. Barnetson notes that as a user is waiting for the hard drive to get up and running, the flash drive can be streaming information out of the cache (see “Starting Your Computer in a Flash”).
Barnetson believes that, while the cost of flash memory is currently too high to offer a 40-gigabyte laptop within the next few years, prices are decreasing by 35-40 percent per year. Devices such as tablet PCs that don’t need as much storage may be the first to arrive with all flash memory hard drives.
Furthermore, David Patterson, professor of electrical engineering at Stanford, suggests that laptops may not need all the storage space that users are currently accustomed to. If more data is stored in networks and accessed via the Internet, Patterson suggests, a 10-gigabyte laptop might suffice. In this case, the laptop’s memory could be reserved for programs that are rewritten less often, keeping the flash memory fresh.
But Patterson also doubts that Flash will entirely replace magnetic hard drives anytime soon. He notes that flash memory wears out after about 100,000 rewrites. This means it’s good for an iPod, where songs are updated every couple of days or so, but bad for software that has to write constantly to a computer’s hard drive.
Samsung has created a program that lessens the wear-and-tear on flash chips by evenly distributing data rewrites, so that one particular cell of the chip is not bombarded with information in rewriting, according to Barnetson. Even so, Patterson says, a cleverly written virus could wipe out an entire flash drive by taking advantage of this weakness.
And flash memory can’t do everything alone. Intel’s Teixeira notes that another issue is to increase bandwidth – the speed at which information is transferred from devices or streamed over networks. Join up flash memory with pumped-up bandwidth, Teixeira says, and “we’re heading toward a ubiquitous computing world where anything has intelligence.”
(For an annotated, warranty-voiding dissection of the iPod nano, see our “Hack” feature in the December 2005/January 2006 issue of Technology Review magazine.)