David Flynn23 May 2007, 11:23 AM
How do you bridge the storage gap between flash disks and hard drives? Lenovo tips a dual-drive system which puts the OS and apps on a flash drive, but uses spinning platters for your data.
No-one seriously doubts that solid state flash drives will one day displace hard disks as the storage medium of choice, especially for notebooks. Memory densities and thus drive capacities are steadily marching upwards while the crucial cost-per-megabyte slowly falls.
At some stage, perhaps before this decade is out, we'll likely see flash drives offered as standard kit on a mainstream notebook.
But before then, flash memory and the conventional hard disk will live side by side -- quite literally, if Lenovo's concept for a 'dual drive' notebook makes it off the drawing board.
Matthew Kohut, the company's worldwide competitive analyst, outlined the concept in a briefing with apcmag.com.
"Probably in the next few years we'll see a dual-drive strategy where your operating system and applications are on solid state media but things like your documents and music and movies are on spinning media. There's no product to speak of yet but I think it's the next thing we'll see, and it makes the most sense because you've got notebook hard drives announced at 250GB but flash memory at only 64GB today, so there's a big gap there."
Kohut also suggested that bullish predictions for solid state media are a little off the mark of what the technology can currently deliver.
"People are expecting solid state memory is going to blow away spinning media. But flash memory today has a limited number of read-write cycles, and the fastest and largest available solid state drives can't get as many read-write cycles as you need for long-term use. You have to go to 'N-1' technology, which are the slower and smaller-capacity solid state drives. It's going to take extra time to get the fastest flash memory up to the number of read-write cycles. With time that will happen, and capacities will keep increasing".
In the meantime, Kohut says the best role for flash is as a cache between the hard drive and the PC's main memory. Most specifically, this is using Intel's Turbo Memory (formerly codenamed Robson) which parks flash memory on the motherboard, rather than hybrid hard disks where the memory is built into the drive itself.
 The sweet spot: Lenovo says 1GB of Turbo Memory in your notebook can deliver "up to a 45% performance increase" |
"If you start with a baseline system of a 5400rpm hard drive, then you make this a hybrid hard drive with 256MB, we've found on our benchmarks that you get around 3% or 4 % performance increase over the baseline" explains Kohut.
"If you add 512MB of Turbo Memory instead of using a hybrid hard drive the gain is maybe 5-6%, but 1GB is where the magic happens. In some cases we're seeing up to a 45% performance increase over a system without Turbo Memory. You also get an additional few minutes of battery life -- it won't be dramatic but every few minutes count."
"We're not saying that we'll never use hybrid hard disks" says Kohut. "The technology is great and it makes a lot of sense, but right now 256MB of hybrid hard disk is the biggest you can get, while with Turbo Memory today the biggest you can get is 1GB, and that's where the sweet spot is. Until you get to that 1GB level you really don't see a big performance boost."