Intel: solid-state drives boost battery life

Intel said Tuesday that solid-state drives can extend battery life up to 30 minutes compared to hard disk drives.

Add the speed advantage of solid state drives and that's two strikes against hard disks. Price parity--strike three--is still a ways off, however. That--and the fact that hard drives offer much larger capacities--will keep hard drives competitive next year.

For now, Intel is evangelizing the benefits of speed and power efficiency.

Most independent benchmarks show that solid state drives perform better than hard disk drives. In some cases, a lot better. That's a given now. One area, however, that isn't so clear cut is power efficiency. Intel tried to lay that argument to rest Tuesday in a conference call.























Intel claims that its SSD extends batter life about 30 minutes on a laptop
(Credit: Intel)

As a preface to the presentation, Knut Grimsrud, Intel fellow and director of storage architecture, made the often-overlooked point that one of the reasons Intel makes solid-state drives is "in order to realize the full value of Intel CPUs." In other words, systems that couple Intel processors with SSDs can deliver better performance overall and do it more efficiently.

In the portion of the presentation focused on power, Grimsrud first compared an Intel SSD with a 5400rpm and 7200rpm hard disk drive. He showed a slide claiming that Intel's SSD spends about 96 percent of its time in low-power states, while a hard drive spends only about 10 percent (see graphic).

Looking at why SSDs are power efficient, he explained that "they way we look at power efficiency is how much power does it takes to get a certain amount of work done."

"So, it's really measure of power per operation performed or operations performed per watt," he said.

While one chart showed an Intel solid state drive's "active power" falling between that of two competing solid-state drives, Grimsrud claimed that Intel's drives get more done in the active state than competitors' drives. "It's how much work are you getting done while you are energized," he said.






















Intel compared time spent in lower-power states between SSDs and HDDs
(Credit: Intel)

More specifically, how much power per I/O (input/output) operation is consumed. "That's really the metric for power efficiency," he said. "A very slow SSD that has low power is not necessarily more power efficient. It's just not getting work done at the same rate," according to Grimsrud.

In a real life scenario, Intel showed three systems: one using a hard disk drive, one using a competitor's SSD, and another an Intel SSD. Both the hard drive and competing SSD ran out of power in four hours, Intel claimed, while its SSD allowed the battery to last another 32 minutes, for about a 13 percent battery life extension.

"We're getting secondary savings that are compounding the benefits. Since the Intel SSD is higher performance than the hard drive, the rest of the system can also enter its lower-power state much more quickly than it otherwise would," he said.

Finally, Grimsrud mentioned the 24-hour battery life achieved by the HP EliteBook 6930p. He said that Intel's SSD contributed to this and that internal HP benchmarks show overall performance boosts of up to 57 percent on industry benchmarks, and data transfer rates almost six times faster than traditional hard disks.