[PLEASE LEAVE ALL ITEMS BETWEEN ***ASTERISKS*** BUT REPLACE ALL ITEMS IN SQUARE BRACKETS WITH YOUR WORDS AS INSTRUCTED]

***FLAG IDENTIFYER***

Storage Technology

***TITLE***

Future Storage Technology

***STANDFIRST***

Magnetic disks are running too hot, crashing too often, and can’t keep pace with our digital media lifestyle. The solution: a replacement technology.

***COVERED IN DETAIL***

***APPLICATIONS***

Hybrid storage
Flash
Phase-Change Memory

Holographic memory

***TECHNOLOGY FOCUS***

- the boxout titles and functions focussed on listed here -

***INTRO TEXT***

Did you know? The magnetic-media disk inside your PC is an aging dinosaur, capable of storing – at most – only about 1TB of files, spinning at a maximum speed of only 10,000 RPM, and running hot enough that it can cause quite a sting if you touch one after it has been running all day in a poorly ventilated PC case. For most advanced PC users, the maximum storage, RPM speed, and heat density issues will eventually become major pitfalls. Large companies have developed countless workarounds for magnetic medium limitations, such as Internet Protocol-based networked disks and iSCSI, disk arrays that use small density drives to control heat, and storage area networks that provide many multiple terabytes of storage.

You might wonder: why is storage such a hot topic? There are two primary reasons. One is that we are all moving to an age when every piece of information we use will be digital. The problem goes far beyond high-definition videos -- which can easily run over 1GB each -- and high-resolution digital camera photos. In an Internet age, we are storing more documentation than every before: legal contracts, published books, real-estate information, automobile registrations – the list is never-ending.

A second reason has to do with corporate compliance. Companies must archive all incoming and outgoing information in a redundant fashion. In a legal processing, they must be able to recall the information with days. Companies such as Google and Microsoft are moving ahead of the curve with server farms that will hold all of this information. If the end is near for magnetic disks, what comes next?

***BODY COPY***

Hybrid Disks
The first, and most imminent, innovation will be hybrid disks that provide an allotment of flash memory on-disk along with the traditional magnetic media. Windows Vista accurately predicted that disk manufacturers such as Samsung and Seagate would release hybrid disks several months after the OS release. Today, you can use a USB flash disk to simulate the speed benefits of a hybrid disk. When you insert the USB disk, Vista will prompt you to activate ReadyBoost for that drive. The OS will then cache commonly used data on the flash portion for a speed boost.

With a hybrid drive, Windows Vista will use the flash portion of the disk automatically for a speed boost, using a technology called ReadyDrive. Similar to ReadyBoost, this technology caches information to the flash disk, which is typically about 256MB in size and located away from the platters on the drive mechanism. Seagate will release a 2.5-inch notebook drive first. The Seagate Momentus 5400 PSD, for example, has specifications that are remarkably similar to current drives: 5400 RPM, 12.5ms seek time, 160GB storage capacity.

The main difference is that the non-volatile flash memory will handle many of the most common read-write tasks in Vista, saving spin cycles, energy use, and providing much faster access. While a typical hard disk drive might expend as much as half of its energy on spinning up the drives, a hybrid drive would run at more like 90% efficiency due to the flash storage being used for the most common tasks.

bodyimage1.jpg
The Samsung prototype hybrid hard disk drive uses a 256MB flash module on the drive in addition to traditional magnetic media platters.

Flash Disks
After hybrid disks, the next technological innovation will be drives that only use flash non-volatile memory. According to Richard Freitas, the Storage Class Memory Researcher at IBM, these flash drives will appear in the next five years as the costs for flash memory go down. (Currently, a flash drive with 160GB of storage would cost more than the entire PC.) The main advantages are speed of access and portability, since flash drives would be much smaller than a magnetic disk, and are not as susceptible to the heat build-up issues of magnetic disks.

“Flash-based storage will be used for mainstream applications: online transaction processing, high-end storage arrays, notebook computers and mobile devices,” says Jame Ervin, a product manager for enterprise-class storage provider StoneFly, Inc. “Since everyone will be extremely concerned with energy conservation, flash offers reduced power consumption, large capacities and high performance for wide ranging applications.”

Another innovation related to an all-flash storage will be a new controller for PCs. If magnetic media really does go the way of the dinosaur, flash memory could change the form factor for the desktop PC into a much smaller device without drives bays or the need for as much cooling. There’s also potential for innovation in IP-based storage (where disks are not connected to a PC at all), which flash-based IP storage would use Gigabit Ethernet or fibre channel to connect to servers in business.

“The major complaints about current magnetic storage media are speed, robustness, and power consumption,” says Freitas. “An effective non-volatile memory technology would yield systems that had significant advantages over current magnetic storage. For example, IBM is exploring alternative approaches to exploiting the underlying technology in Magnetoresistive Random Access Memory (MRAM).”

Phase-Change Memory
One of the major problems with flash memory – both for hybrid drives and as an all-flash hard disk drive – is that data can only be written to the disk 100,000 before it starts to degrade severely and will fail. That’s why, today, flash media is used mostly as a temporary storage media on digital cameras and on USB keydrives.

Phase-change memory – which is a technology that is being independently developed by Intel, Samsung and IBM – has two distinct advantages over flash memory. One is that it runs 500 times faster due to how the process of handling data occurs. Nanometer-sized semiconductor alloy fibres change quickly between a low-power crystalline state and a more high-power amorphous. This process is lightening quick, as opposed to the more mechanical magnetization that occurs with current generation hard disks, and uses very little power.

Another key advantage is that an electrical charge is not required to keep the alloy in either the crystalline or amorphous state, so it is non-volatile and does not consume as much power as flash or magnetic media. There are no theoretical limits to the number of times that the alloy can be charged, so data can be preserved for much longer periods than flash – more than 50 years. This low-power, long-life capability is attractive for storage because it means archiving important data – such as the financial records at a company or precious photos – without as much concern or media failure.

A third advantage over flash memory and magnetic media has to do with the size of the chip. Magnetic media uses platters that are formed in a set size to fit the design of current PC cases – typically either 2.5-inch or 3.5-inch. Meanwhile, flash memory has a slight leakage problem at 45nm sizes that is not significant enough to cause data loss, but the leakage becomes much more problematic at sizes below 45nm. Flash media will likely not get much smaller than the current generation chips for this reason. Phase-change memory does not have a leakage problem even at sub-45nm sizes. This means a phase-change disk could be embedded into a cell phone, or vehicle steering column, or sunglasses, at sizes over 1TB in the future.

"If phase-change memory can live up to its promise, it would revolutionize the computer industry within 10 years,” says Spike Narayan, the Senior Manager of Nanoscale Science and Technology at the IBM Almaden Research Center. “Imagine a non-volatile memory 500 times faster than flash with the write-endurance to be used in mainline computer systems. Mobile electronic and computers would then have the speed and power for handling tasks far more demanding than is now possible. If volume manufacturing makes phase-change memory cheap enough, it could even start replacing disk drives, because it would be up to a thousand times faster, consume very little power and potentially more reliable because it will be all solid state."

Bodyimage2.jpg
Phase-change memory has distinct advantages over flash-based media, including speed of access and longevity for mission critical data storage.

Bodyimage3.jpg

Phase-change uses a chemical process to convert materials from one state to another and could potentially last for 50 years.

Holographic memory
Phase-change memory has some remarkable benefits for future storage requirements, but the one unknown is how much it will cost. Companies such as Intel and IBM are also still in the early stages of development. Holographic storage is both a near-term possibility for storage, and one that has potential for long-term adoption. Currently, the technology is in a proof-of-concept stage where companies such as Sony and InPhase have demonstrated a write-once storage medium (which means it is only useful as a long-term archival technology), but in the next few years, may develop holographic memory for PC storage that is read and write capable.

Holographic storage works the same as a holographic video -- when you change the viewing angle, you can see a different image. With traditional storage media, data is written in one data bit at a time to a flat media, such as a magnetic strip or a flash memory disk. Holographic technology writes millions of bits at a time to a light-sensitive material that can contain data using a chemical reaction. A laser splits light into two beams for writing and reading the data. After each transfer, the beams switch position slightly to write on a new location of the medium (thus the holographic comparison). The only current problem with this technique is that, as much media as you can store on the medium (there is no theoretical limit) and as many times as you can write to it during one transfer (it’s nearly infinite), the material is not rewriteable. This is an important distinction because it means holographic storage is ideal for long-term archiving of important corporate data, or movie footage that a studio would like to preserve for decades, but it is not ideal as a reusable consumer technology.

“Holographic storage is a new form of optical based medium that has the promise of higher capacity for archiving and long term data preservation capabilities,” says Greg Shulz, the founder and senior analyst at Storage IO. “Holographic storage is very much in its infancy with initial prototypes and beta taking place now and general availability expected later in 2007 with continued roll out over the next couple of years with higher capacities and performance enhancements from vendors like Inphase. With adoption should also come lower costs.” 

“With high densities -- 80GB or more -- in a tiny-sized package, holographic technologies will revolutionize content delivery,” adds StoneFly’s Ervin “Soon we will have an entire year's worth of movies, TV series or back catalogue of music in a small package. These sorts of technologies will offer an easy option to archive media libraries and create music and movie jukeboxes with years worth of content. I think we may also see other interesting consumer-level applications for the travel industry:  imagine offering an in-flight rental of the entire Disney catalogue for each parent on the plane in a small player for each child to watch during the flight.”

Bodyimage4.jpg
Holographic storage cartridges such as this one from InPhase Technologies can store hundreds of GBs on a write-once media for archival movie storage.

Bodyimage5.jpg

Holographic storage works by splitting a laser beam into two patterns to store data bits, then shifting the lens slightly for another storage render.

Bodyimage6.jpg
The Holographic reader, such as the Tapestry 300R reader from InPhase Technologies, reads data from a holographic data cartridge.

Boxout One: The 15,000 RPM Drive

One way to address the storage challenges of tomorrow is to increase the capacity, speed, and reliability of magnetic disks. Two companies are at the forefront of magnetic storage research: Seagate and Hitachi. Hitachi recently released the highest capacity magnetic media drive, which holds 1TB of data.

“To increase capacity, we have increased the areal density in bits per square inch on the disk,” says John Best, Chief Technologist at Hitachi GST. “The new technology that enables this is called perpendicular magnetic recording (PMR). With our terabyte drive, we have transitioned to PMR technology. This allows for increased areal density (and thus, capacity) beyond current longitudinal recording technology. With perpendicular recording, the magnetic orientation of the data bits is aligned vertically, perpendicular to the disk. In this orientation, materials and smaller crystalline grains can be used wherein it is harder to reverse the magnetic orientation, resulting in smaller physical bits that are still stable at room temperature.”

Meanwhile, Seagate has released a 15,000RPM drive used for enterprise-class storage that runs faster than any consumer drive. It’s unlikely that hard disk drive companies will develop faster running hard drives because of the related heat issues.

Image: boxout1.jpg

Seagate has developed the fastest spinning magnetic hard disk drive in existence, used primarily in data centres for enterprise storage in servers and server racks.

Boxout Two: Magnetic Disk Timeline

1950s: IBM develops the RAMDAC disk drive with a 5MB capacity. Each drive had 50 disks, each one 24-inches in diameter, and could only store 2000 pages of text.

1979: Seagate releases the ST506 5.25-inch hard disk drive, with a 5MB capacity. The drive spins at 3600RPM. Can read and write 12 records per second.

1980s: The 3.5-inch hard disk form factor starts to replace the 5.25-inch size.

1990s: The 2.5-inch form factor used in laptops starts to replace the 3.5-inch form factor in data centres for corporate storage.

2000: Hard disk drives start using perpendicular recording methods to increase speed and capacity.

2006: The Seagate Savvio disk is for enterprise data centre use. It spins at 10,000RPM and holds 146GB with a data transfer rate of 85MBps.

Image: boxout2.jpg
Seagate is one of the leaders in developing new hard disk drive technologies.

Boxout Three: Hard Disk Crashes: Ancient History?

One of the major innovations of holographic storage is that the data – once written to the substrate material – stays in that locked state for up to 50 years. It means the lifespan of holographic media is long enough that companies and consumers could use this storage method for permanent archives without the risk of a hard disk crash that destroys all of the data. Other advantages, such as speed and capacity – make it a contender for future storage methods – if companies can determine how to make the media more affordable for consumers and develop a way to make the media rewriteable for consumer applications, such as digital cameras and laptops.

“The advantages of holographic storage are unlimited storage capacities -- since the theoretical limit has yet to be calculated -- tremendous transfer rates of 80 GBps, unprecedented physical security – since the recording is volumetric, meaning it is in the actual physical layer of the disc, so that content holders can create their own, independent, physical security keys – and extremely long life, since a 50-year life cycle is unprecedented for optical or magnetic recording media,” says Chris Pfaff, an InPhase Technology spokesperson in charge of business development.

***FAST FACTS***

1. Seagate developed the first commercially available, consumer hard disk in 1979 that could hold only 5MB of data.

2. There is no theoretical limit to the capacity of a holographic storage device, since the laser beam that writes data can shift in an infinite number of record patterns.

3. Windows Vista automatically uses the available flash memory on a hybrid drive without any additional user interaction.

***BIOG***

John Brandon has written over 700 feature articles on PC technology and wireless networking. Before writing full-time, he was an enterprise director at a large consumer electronics retailer in the US. Reach him at: john.brandon@pcplus.co.uk.