OPTICAL STORAGE - Do the write thing

As the demand for extra storage capacity snowballs, resellers are having to find alternatives to CD-Rom. But with the myriad of standards and formats available, it's far from straightforward.

Computer users are forever banging on the door of dealers demandingaving to find alternatives to CD-Rom. But with the myriad of standards and formats available, it's far from straightforward. more storage capacity. It must be removable and it must be rewritable, they shout. Unfortunately for the margin-starved reseller, the greatest demand is that it must be cheap.

Although the price of hard disks continues to fall and removable technologies such as Jaz offer high capacity points, the mass market in removable storage is moving towards optical disks. Sales of rewritable CD drives have mushroomed over the past three years and analysts predict that this format will generate more revenue than read-only CD-Rom drives this year (see chart below).

Soon, multi-gigabyte, re-writable DVD drives will be selling in quantity - their disks already cost little more than a ha'penny a megabyte.

This year's darlings of the channel will be CD-RW (rewritable) drives, which can read and write virtually all formats of CD. Europe is the world's top market for CD-RW and its half-brother CD-R (write-once), accounting for 40 per cent of worldwide sales, which are estimated at 15 million for 1999.

'One of the reasons demand is going up is that the price has come down to consumer levels,' says Jim Corbett, general manager of Yamaha's media technology division. 'Two years ago, only professional users such as graphic designers and video editors bought these units. Now they're being used for downloading from the internet, games and audio copying, video editing and consumer applications.'

CD-RW prices have plummeted in the past year from between #600 and #700 to between #150 and #300. Sales of high-capacity DVD-Rom readers are also expected to increase and both products are expected to be in short supply, at least for the first half of the year. 'Our expectation is that in the second half of 1999 the supply will ease, drive manufacturers will be able to start addressing the large OEM market and prices will fall to nearer $100 per unit,' says Bob Peyton, director of European storage research at IDC.

A further price fall will be critical to mass take-up of CD-RW and DVD-Rom by PC makers. A few, such as Viglen, Dan and Evesham Micro, already include them in high-specification PCs, but most vendors are hanging back.

'We estimate that the majority of these drives are sold as upgrades rather than installed into PCs, because PC manufacturers are still looking at lowest cost components to keep prices down,' says Mick Duffy, sales and marketing director of PC peripherals at Philips.

As CD-RW and DVD-Rom prices fall, CD-Rom will fade away by 2001 or 2002, according to industry observers. Another loser is expected to be CD-R, whose function will be overtaken by CD-RW. Magnetic removables will not be safe either. Last year, CD-RW and CD-R drives outsold zip and LS-120 drives - even at three times the price - and sales of high-capacity removables such as Jaz are in decline.

In theory, rewritable DVD technologies such as DVD-Ram or DVD+RW should be even more attractive but, in the short term, a lack of standards - not to say product - will hold them back. 'The nice thing about CD-RW is that there is a final standard,' says Robin Burke, principal European storage analyst at Dataquest. 'If there isn't a similar standard for rewritable DVD, I don't think there will be a big take-up.' Peter Nordwall, software marketing manager at Adaptec, agrees: 'The standard which comes out on top will be the one with the greatest compatibility with existing formats,' he says. 'We believe CD-RW will be strong for some time, just because of its compatibility.'

Recordable media has also become big business, with nearly 250 manufacturers churning out CD-RW disks and especially CD-R disks, which out-sell CD-RW by 10 to one. As with floppy disks, the quality varies, with brands such as TDK, Mitsui, Fuji and Kodak proving more reliable than the no-name clones. Early fears that the coating on CD-R disks would disintegrate after a few years seem to have died down and the disks are likely to prove more durable than magnetic tape. But they are vulnerable to light and can quickly deteriorate if left in the sun.

There is a bewildering array of optical storage products for dealers to get to grips with, but there are two simple keys to understanding them.

The initials before the hyphen indicate the basic format and capacity.

CD holds about 650Mb of data. DVD holds much more data - currently between 2.6Gb and 4.7Gb depending on the type. The initials after the hyphen indicate whether data can be written to the disk. Rom (read-only memory) disks are pre-recorded and cannot be altered. R (recordable) and Worm (write-once, read-many) disk can be written to, but not erased or over-written.

RW (read/writable) and Ram (random-access memory) disks can be written and rewritten multiple times.

The different flavours

To put it simply, optical technologies boil down to four main types: Read-only optical, such as CD-Rom and DVD-Rom; write-once optical, notably CD-R and DVD-R; re-writable optical, including CD-RW, DVD-Ram and DVD+RW; and magneto-optical (MO) formats, most of them rewritable, which form a specialist market.

Although some Japanese manufacturers are getting out of CD-Rom in favour of DVD-Rom or CD-RW, the medium is a favoured universal standard, with a worldwide installed base of about 700 million. But because it uses a mass manufacturing process, it is uneconomic to produce just a few copies.

CD-Rom drives can read CD-Rom, CD-R and CD-audio, plus some special CD standards such as Photo-CD and Video-CD. They can also read CD-RW disks if the drive has multi-read technology. CD read speed is measured in multiples of the original CD-Rom speed - 32x is common now, but 40x, 44x and even 48x drives are available, although there is doubt over whether these result in faster data throughput because beyond 32x, the number of errors and re-reads increases. Sony - one of the inventors of CDs - has decided not to develop drives faster than 32x. Other manufacturers admit that they are being pushed into making higher-speed CD-Rom drives to satisfy PC manufacturers, who just want higher numbers to put in the specs of their machines.

Similar to CD-Rom is CD-R, which also has a capacity of 650Mb. Manufacturers include Philips (also re-badged by Hewlett Packard), Yamaha, Sony, Trax, Mitsumi and several others. But CD-R is rapidly losing ground to CD-RW.

Philips has stopped making CD-R drives, while Sony has only one CD-R product.

Once recorded, a CD-R works exactly like a CD-Rom, so it can be read in any CD-Rom-compatible drive. The disks have a layer of dye, which is permanently modified by the laser when the data is written, so each bit on the disk can only be written to once. CD-R drives can write CD-Rs and read anything a CD-Rom drive can read. Older drives had to write the whole disk in a single pass, but newer drives are multi-session and can write data a section at a time, allowing content to be built up over time.

Now that many documents or graphics files are too big to fit on a floppy disk, CD-R is ideal for distributing or publishing a small number of copies of catalogues and presentations. It is also popular for archiving and back-up of medium-sized files and for storing large files such as graphic images.

Consumers mostly use CD-R for copying music CDs or games although, for copyright reasons, they may not admit to it. Archiving and back-up could be target markets for dealers, as could storage and distribution of academic course work, family photograph albums and pictures from digital cameras.

The growing market in online music distribution should also boost CD-R sales.

The write stuff

However, the read-only or write-once format is coming under pressure from CD-RW with manufacturers such as Philips Yamaha, Sony, JVC and several others shipping product. CD-RW has a capacity of between 500 and 650Mb and the disks can be recorded, erased and re-recorded, using a crystalline layer whose reflectivity can be changed by heating with a laser beam.

CD-RW is an established standard, so all CD-RW drives can exchange disks.

CD-RW is not quite as universal as CD-R and CD-Rom, but most drives which can read CD-R and CD-Rom can also read CD-RW, as long as they are multi-read.

CD-RW drives can write CD-RW and CD-R disks, making them highly versatile.

They can read CD-Rom, CD-R, CD-audio and CD-RW. The next development will be CD-RW drives that also read DVD-Roms, which will probably be available by the end of the year. Windows and other operating systems do not support CD-RW or CD-R formats directly, which used to make them very awkward to use. But software products such as Adaptec's Direct CD and Easy CD Creator offer drivers and interfaces which allow writable CDs to be used as drag-and-drop devices like a hard or floppy disk.

CD-RW speed is usually represented as three figures, where the first is the write speed, the second is the rewrite speed, and the third is the read speed. Sometimes rewriting is slower than writing, because the original information must be erased first.

Today's fast CD-RW drives are 4x, 24x - ie 4x writing and rewriting, and 24x reading, which is a little slower than standard CD-Rom drives. Read speeds are expected to reach 32x this year, effectively equal to CD-Rom, enabling CD-RW drives to replace CD-Rom drives. Write speeds are increasing, too, with 6x and 8x already announced or expected at CeBit.

All kinds of PC users could benefit from CD-RW. Most buyers have been businesses, but dealers will witness a consumer uptake as prices fall.

The majority of disks written on CD-RW drives will actually be CD-Rs, because of the much lower media cost, so all CD-R applications are also relevant to CD-RW drives.

Specific CD-RW applications are more limited. They are often used to test CD-Rs, getting the content right using a re-usable disk, rather than making mistakes on a non-erasable medium. Much standard back-up software now supports optical drives, and back-ups could be done using a weekly cycle of CD-RW disks.

'The cost per gigabyte is not much higher than tape, but the ease and speed of getting files back is much greater,' says Alan Russell, UK sales and marketing director of NSM Jukebox, which makes CD and DVD-based jukeboxes.

The slow speed of CD-RW will always rule it out as a full hard disk replacement.

But it could be used to store certain categories of files, such as free software gleaned from magazine cover disks, or an individual's files on a shared PC, eg at home or at school.

The DVD generation

Originally, DVD-Rom had a capacity of 2.6Gb per side, but this will increase to 4.7Gb later this year. With double-layer technology, which uses two different wavelengths of laser light, a DVD disk could hold up to 9Gb of data per side. Manufacturers include the likes of Hitachi and Toshiba as well as an increasing number of big-name drive manufacturers.

DVD-Rom disks are read-only media - the same size and appearance as a CD-Rom, but a shorter wave laser allows more accurate reading and therefore a higher data density. It also allows disks to be double-sided. After much initial argument, there is now a single technical standard for DVD-Rom (although there is more than one standard for high-quality audio).

Computer DVD-Roms are universal and can be read by any DVD reader.

But movie DVD-Roms have been divided into five geographical regions such as the US, Europe, Japan - at the insistence of the movie studios - to maintain closer control of distribution and to forestall pirate copying.

Theoretically, DVD-Rom drives should only read movie disks from one region.

In practice, the region can often be reset a few times (typically five) before becoming permanent, allowing manufacturers to produce a single product for sale throughout the world.

Because it is relatively new, and has been delayed by standards battles, DVD is short on published content. Very little PC software has yet been published on DVD-Rom, although this is expected to increase this year (Intel is pushing the medium, and there are reported to be 350 DVD software titles under development). But while there are more than 2,000 movie titles in US format, there are little more than 100 in Europe.

DVD-Rom drives can read all the main forms of CD - CD-Rom, CD-R, CD-RW and CD-audio - plus DVD-Rom, DVD-R and DVD movies. They cannot yet read rewritable DVDs such as DVD-Ram or DVD+RW, although DVD-Ram compatibility is expected by the summer.

DVD speeds are measured on a different scale from CDs, so 1x DVD speed is equivalent to about 20x CD speed. Standard DVD-Rom drives read at 2x, with 4x and even 6x models available. To date, most DVD-Rom users are buyers of high-end multimedia PCs on which it is a standard item, or people who know they will want DVD in future. Within a year or two, almost anyone who buys a multimedia PC will find one already installed.

Moving a rung up the DVD ladder comes DVD-R which boasts a capacity of nearly 4Gb. Pioneer is the main manufacturer. It is a write-once technology similar to CD-R, but with DVD-type data density. But unlike the rewritable DVD standards, DVD-R can write disks to the DVD movie-quality standard.

DVD-R drives can write DVD-Rs, including professional movie and audio quality, and also read CD, DVD-Rom and DVD movie formats. The speed is similar to DVD-Ram. But with DVD-R, drives cost about #10,000 and disks cost about #50 each which means the market is very niche - mostly film studios and other multimedia professionals who want to produce high-quality movie and multi-media output, eg master copies, screen tests and samples.

Higher still, comes DVD-Ram which has a capacity of 2.6Gb per side. This will increase over time, and is expected to reach 4.7Gb per side by the end of the year - the same as DVD-Rom. After another year it may increase to 8Gb or 9Gb per side. Manufacturers include Panasonic and LaCie.

DVD-Ram is the first of several mutually incompatible types of rewritable DVD to appear - the first DVD-Ram drives were launched last autumn. The recording technology is similar to CD-RW, but the data structure and physical structure makes DVD-Ram significantly different from DVD-Rom, and this - say many of its opponents - makes it more expensive to build multi-standard drives which include DVD-Ram compatibility.

Unlike other standards such as DVD-Rom and DVD+RW, each DVD-Ram disk is encased in a plastic cartridge (caddy), for protection and more accurate insertion. There are two types of cartridge - one type allows the disk to be removed for insertion in another drive, such as a DVD-Rom, the other type doesn't.

DVD-Ram drives can record DVD-Ram and PD disks, but not the other recordable DVD standards. Most can read CD-Rom, CD-R, CD-RW and CD-audio, but not necessarily DVD-Rom, DVD movies, DVD-R or DVD+RW. Manufacturers claim that by the summer, DVD-Ram drives will also be able to read DVD-Rom, and maybe DVD+ RW. DVD-Ram drives cannot record DVD movies, partly because these are copy-protected, and also because today's read-only DVDs have a higher capacity than DVD-Ram. Nor can they easily record digital TV because of the complexities of encoding and playback.

DVD-Ram drives commonly write at 1x speed and read at 2x, like a standard DVD-Rom drive. User prices are between #300 and #400. Disks sell for about #15 each (so they are cheaper per megabyte than CD-RW).

Potential buyers include almost anyone who needs very large scale data storage. Early business adopters could include designers, architects, multimedia professionals, pre-press and publishing firms. Applications could include anything that CD-R or CD-RW are used for, but requiring bigger capacity. Large back-ups fit more easily, and DVD is being used for storing and editing large projects, such as Web page design.

And finally comes DVD+RW. The capacity of DVD+RW is currently 3Gb per side. It is expected to be 4.7Gb per side within two or three years. The main manufacturers are Sony, Philips and Hewlett Packard.

DVD+RW uses a similar physical medium to DVD-Ram, but the data and physical structures of the disk are more similar to standard DVD-Rom. Manufacturers claim this will make it cheaper to build DVD+RW compatibility into other DVD drives, but it also means that DVD+RW is not compatible with DVD RAM.

The DVD+RW standard is not finalised yet and drives are not expected to appear until mid-year. Even then, supply will be limited and manufacturers have not decided which geographical regions to target first.

When available, DVD+RW drives will be able to record DVD+RW disks, but not the other rewritable DVD standards. They should be able to read CD-Rom, CD-R, CD-RW and CD-audio, and hopefully DVD-Rom, DVD movies and DVD-R, but not necessarily DVD-Ram or the other DVD rewritables.

The speed of DVD+RW will probably be similar to DVD-Ram. The cost of drives is not decided. But manufacturers claim that they will be cheaper to make than DVD-Ram drives, and experience suggests that, being second to market, they will have to match or undercut DVD-Ram prices. Disks should also cost no more than DVD-Rams. Confused? You must be.

MAGNETO-OPTICAL DEVICES

Magneto-optical (MO) disks are different from purely optical CD and DVD. When writing or erasing data, they use a laser to heat the disk, which allows the magnetic field to be changed. Reading is done magnetically, which lets MO drives operate more like a hard disk, with formats and sectors which allow faster addressing. As a result, access times are not much slower than a hard disk - between 20ms and 25ms, compared with about 100ms for a CD or DVD.

There are three main types. 3.5ins rewritable disks hold about 640Mb, though a new format, GigaMO, holding 1.3Gb, will start shipping in March.

Basic drives cost #200-#300, and disks about #20.

The 5.25ins rewritable MOs hold up to 5.2Gb (2.6Gb per side), which will increase to more than 9Gb in a year or so. Drives cost between #600 and #1,500, disks about #70. The 12ins MOs are Worm devices, such as a CD-R or DVD-R. They are very expensive and very specialised, with only a few dozen drives sold in Britain each year.

MO disks have various advantages over writable CD and DVD. As well as being faster, they are more durable, with the media guaranteed for 30-100 years. They verify after each write, making them a more reliable back-up and archiving medium.

They are fully supported by the main operating systems, they come with all the main interfaces - SCSI, IDE, parallel, USB and IEEE 1394 - and they can be made into a bootable disk, just like a hard disk or floppy.

And today's drives have full backwards compatibility, being able to read (though not write to) MO disks going back to the 80s.

MO drives are straightforward to sell.

'I don't think these devices are going to create any challenges for the average PC dealer,' says Neville Wheeler, general manager at Fujitsu Europe.

But MO remains a niche and sales are falling (see chart, page 43). Back-up and archiving are the key uses, together with storage of libraries of large images, such as x-rays, and document-imaging in areas such as financial services. Some educational institutions give them to students to keep their personal work on, and being bootable they can be used for restarting systems during disaster recovery.