Discovering DVD-RAM

A reliable format for data-storage applications

The pursuit of more storage space in smaller, more mobile packages, such as 100MB Zip disks and 120MB SuperDisks, dominates the computer industry. Some of the first removable storage media on IBM-compatible systems were single- and double-sided disks that held 360KB and 720KB of data, respectively. Since then, engineers have developed a variety of removable storage media that hold greater amounts of data without being unwieldy. At the time of their inception, those storage media seem adequate, but the need for additional and more mobile storage alternatives quickly outgrows the latest storage technology.

Until recently, no product has been available for users who want to use multiple removable storage devices in one system. If users want to read CD-ROMs and DVD-ROMs, they purchase a DVD-ROM player, but the device can't write to discs. If users want to write to CD-ROMs, they purchase a CD-Rewritable (CD-RW) device, but the device can't read DVD-ROMs. Neither DVD-ROM nor CD-RW devices are a complete solution for users who want to read CD-ROMs and DVD-ROMs and use one device to store data. However, DVD-RAM drives now provide users with this functionality.

In 1997, the DVD Forum defined a standard for rewritable storage—DVD-RAM. DVD-RAM's founders sought to provide a format for data-storage applications that offers reliability, high data integrity, affordability, and compatibility. Compatibility is important so you can play all forms of CD-ROM, such as high-capacity DVD-RAM and DVD-ROM, CD-ROM, and CD-Recordable (CD-R) discs, from the same device.

DVD-RAM drives read and write to 4.5" * 5.25" removable cartridges. In addition, they read DVD-ROM, DVD-Recordable (DVD-R), audio CD, CD-R, CD-RW, and CD-Interactive (CD-I) media. Vendors offer DVD-RAMs in single-sided 2.6GB or double-sided 5.2GB formats.

To format DVD-RAMs for a Windows NT system, you must use Software Architects' (http://www.softarch.com) FormatterOne Pro DVD on NT software. Most DVD-RAM drives don't include this software, but you can purchase it from a vendor when you buy the drive. Vendors usually preformat DVD-RAMs as FAT16. Although I used NT's Disk Administrator to format DVD-RAMs as NTFS, I couldn't find any vendor documentation to support this method. This lack of compatibility results from vendors' focus on DVD-RAM in the Windows 9x market rather than in the NT arena.

To reformat a FAT16-formatted DVD-RAM, open Disk Administrator, which lets Disk Administrator write a signature to the disc, save the configuration changes, and exit Disk Administrator. You can now format the disc by selecting the drive in My Computer and selecting NTFS as the file system in the Format dialog box. I formatted one side of a DVD-RAM in about 20 seconds.

Additional data security is one benefit of formatting DVD-RAMs as NTFS, but a disadvantage is that you can't share the disc with other OSs. Software Architects is developing Universal Disk Format (UDF) for NT, which will let you share DVD-RAMs among multiple OSs.

Most DVD-RAM drives include audio input connectors that you connect to a sound card to play audio CDs. To view DVD-Video, you must purchase a separate Moving Pictures Experts Group (MPEG)-2 decoder card.

DVD-RAMs aren't susceptible to magnetic fields, which helps protect your data from accidental erasure. In addition, the laser head never physically contacts the media, so you won't experience the media damage problems that physical contact can create. Also, you can expect your DVD-RAMs to last at least 50 years, and they cost less than 1 cent per megabyte.

Pinnacle Micro and LaCie DVD-RAM Drives
To test the capabilities of DVD-RAM drives, I used Pinnacle Micro's Flex DVD-RAM drive and LaCie's SCSI DVD-RAM drive. The drives are similar, although the Flex drive is half the height of LaCie's drive. I tested both drives on a 300MHz HP Kayak XW with 128MB of RAM running NT Workstation 4.0 with Service Pack 3 (SP3).

I used the same process to install both drives. You must have a SCSI adapter installed in the system that you're connecting the DVD-RAM drive to. Neither drive I tested included a SCSI card—you must purchase one separately. Most SCSI cards will work, but LaCie recommends that you use Adaptec SCSI adapters. To set up the drives, you connect them to the system via a SCSI cable. LaCie and Pinnacle Micro provided informative guides that simplified setup.

Next, I installed FormatterOne Pro on the test system. After I inserted the 3.5" disk, a wizard led me through a few setup screens. The system rebooted 20 seconds later, and I was ready to go. I used a separate preformatted 2.6GB disc to test each drive. Both drives support 5.2GB double-sided discs. You access each side's storage space by flipping the disc and inserting the appropriate side into the drive. When I opened FormatterOne Pro from the Start menu, the software presented me with an interface through which I located the DVD-RAM drives. To find the drives, I clicked Adapter and selected the port on which the drives were located. The vendors preformatted both 2.6GB test discs as FAT16, so I exited the program and used Disk Administrator to reformat one disc on each DVD-RAM drive as NTFS.

On my test system, I created a folder that contained 1267 word processing, spreadsheet, database, and multimedia files that ranged in size from 25KB to 7.2MB and totaled 45.1MB. I transferred these files from the test system to a 2.6GB disc. LaCie's drive completed the file transfer in 6 minutes, and Pinnacle Micro's drive completed the file transfer in just over 10 minutes. I reformatted the discs, traded discs between drives, and ran the test again. The results were consistent with the first test. Reading DVD-RAM, the average seek time for LaCie's SCSI DVD-RAM drive was 180 milliseconds compared with 200 milliseconds for Pinnacle Micro's Flex DVD-RAM drive. However, both products claim a sustained data transfer rate of 1.38MBps.

Do You Need DVD-RAM?
The answer depends on your needs. Everyone can use more storage space, and DVD-RAM is removable, so you can take a DVD-RAM disc to another location and use it in another DVD-RAM drive. For example, content creators can store data, slip the disc into their briefcase, and use it at another location. Database administrators (DBAs) and application developers can use DVD-RAM to share file creation with their peers. In addition, you can use DVD-RAM to archive backup storage and send the disk offsite for added security. If you're looking for a mobile storage medium that stores more than 650MB per disc, and you can afford $799 for DVD-RAM drives at each necessary location, LaCie and Pinnacle Micro offer useful drives at a good price.