AfterDawn: Glossary


DVD-RAM is a competing DVD Re-Writable format with many advantages over its rivals. DVD-RAM stands for DVD-Random Access Memory, a name given to the format that is widely debated. The problem some people find with the "RAM" part of the name, is that DVD-RAM is not really "Random Access Memory" - the name really gives a comparison between DVD-RAM and other format such as DVD-RW because of its "Random Access" capabilities (that we will look at a little later). Beyond the name, DVD-RAM surpasses other recordable DVD media in many ways whether its a question of reliability, quality, speed or ease of use. In this glossary item we will take a look at this excellent format and what it has to offer for you.

In this glossary item, we are lucky enough to have some answers from Tony Jasionowski of the DVD-RAM Promotion Group to publish. These were kindly given to AfterDawn by RAMPRG (the DVD-RAM Promotion Group) after we were offered a discussion in late 2005. Reading through this glossary item, you will find some quotes from Mr. Jasionowski.

Wide Variety of Uses

A major selling point about DVD-RAM is the number of uses it is suitable for. A variety of factors such as Random Access, Defect Management & Advanced Editing Functions make the format suitable for home users and professionals alike. DVD-RAM really stands out by being fully support by the Microsoft Windows XP operating system. FAT32 formatted DVD-RAM discs can be written to directly by Windows XP without the need for further driver installations. A driver is needed to write however if you are using an older Windows OS or UDF-formatted discs (you need software like InCD with Windows XP for UDF).

"There’s no question that write-once media (DVD-R and +R) are generally more available, more affordable and more widely used because of their high degree of compatibility with legacy DVD video players. However, DVD-RAM has always been the leading rewriteable format in consumer set-top box recorders and is growing rapidly in the PC space, especially laptop computers and now desktop PCs due to companies like HP agreeing to incorporate DVD-RAM into their products." - Tony Jasionowski.

DVD-RAM discs are commonly used in DVD Recorder Equipment and Camcorders. Due to the availability of fast On-Disc Editing, storing your own recordings on DVD-RAM has advantages over storing on other formats. Also, imagine using the disc like a hard disk drive, using the same disc to store data from several sources whether its a DVD recorder, Camcorder or just plain computer files. RAM-compatible hardware can read/write a DVD-RAM disc containing mixed data types.

DVD-RAM's random access capabilities give it more of an edge over its rivals also.

"DVD-RAM's growth, past, present and future is attributable to a number of factors. DVD-RAM features a variety of advantages that are unique among the five rewriteable DVD formats. These include the highest available rewriting speed, fast formatting capability, and built in defect management system. Also DVD-RAM can be rewritten more than 10,000 times, which is much more than other rewriteable formats." - Tony Jasionowski.

Random Access

Simultaneously recording and playing back content is possible with DVD-RAM thanks to its Random Access capabilities. Like a hard disk drive, instant random access to any location on the disc is possible, making DVD-RAM much faster. RAMPRG exposes the secret as address information located every 2kb immediately before user data while other formats' address information is not as close to user data (some as high as every 32kb).

"DVD-RAM is the only rewriteable DVD disc which is designed with pre-embossed address marks for random access much like that of a hard disc drive, allowing instant, random access to any location on the disc. This random access makes simultaneous recording and playback possible. This also makes DVD-RAM the fastest format to access your data." - Tony Jasionowski.

Another nice point about DVD-RAM is how quickly a disc is formatted before first use. Most users of Re-Writeable media have had to sit and wait for 30 seconds to 2 minutes before data recording even initiates when they first use a disc. With DVD-RAM, the estimated time to format is between 2 and 10 seconds. Finalising also takes siginificantly less time. (Of course, certain factors may produce different results).

The Speed of DVD-RAM

When choosing recordable DVD discs, consumers often go for the fastest option. 12X DVD-RAM was released in January 2006. Before that, in 2004, DVD-RAM was then the fastest Re-Writable DVD media available on the market with the release of 5X media. Additionally, 16X DVD-RAM format was approved by the DVD Forum in Sept. 2005 and could be available in the near future.

Defect Management

The most important thing about blank DVD media is reliability. Consumers have to be sure that their data is safe. Experts have agreed that users are less likely to have technical problems if they choose DVD-RAM over other Re-Writeable formats. There is no need for manual data verification via special software, with DVD-RAM, hardware verification of written data is automatic. If you have accidentally damaged your blank disc and you burn data to it, it is automatically compared with the original data. If it can not be verified, the DVD-RAM drive will use a spare area on the disc to write the unreadable data again and run verification again. This offers the ultimate safety of your data. Additionally, another major selling point of DVD-RAM is the minimum 30 years data retention (if the disc is kept undamaged).

"The last thing consumers should have to worry about is data verification. One of the unique features of DVD-RAM is that it has a built-in defect management system. The defect management system automatically verifies and confirms data that is recording against the original data, ensuring accuracy. This translates into a more robust and reliable recording of your valued data without the use of any external software." - Tony Jasionowski.


With next generation optical disc formats arriving on the market, soon it will be possible to fit much more data on a disc than DVD-RAM or any of the other DVD formats can offer. This is possible by utilizing a blue laser instead of a red laser used with DVD. However, even with the higher storage capacity possibilities, the future is still bright for DVD-RAM. I asked Tony Jasionowski this question and he gave this response:

"With all of the next generation hype, the fact remains that true HD content is still not widely available, is extremely expensive and is not compatible on most consumer’s current analog television sets. As the debate over next generation blue laser formats continues, most industry watchers and journalists are overlooking what is the biggest consumer electronics success story in history—the success and continued growth of current red laser DVD recorders. This year marks the turning point as more consumers replace their home VCRs with DVD recorders. Even DVD Players are being displaced by DVD recorders. According to Semico Research Corp, DVD recorders are rapidly taking the place of the VCR, and are forecasted to grow from 22.8 million units this year to 86.9 million by 2009. This year alone, DVD recorder revenues are expected to reach $6.3 billion. With that said, the DVD-RAM Promotions Group expects DVD-RAM to experience great success well into 2010 and beyond." he said.

More DVD-RAM Facts

  • DVD-RAM discs are sold with or without cartridges. Originally they were sold only in cartridges but now some RAM-compatible devices don't even support those discs anymore. A disc with a protective cartridge costs more.
  • DVD-RAM does not use Magneto-Optical technology despite being widely believed to do so.
  • Linux supports DVD-RAM operation directly
  • Mac OS (v8.6 or later) supports DVD-RAM operation directly.
  • DVD-RAM discs can be single sided 4.7GB one layer discs or double sided 9.4GB one layer discs. 80mm 1.46GB discs are also available.
  • Most stand-alone DVD players and recorders, particularly older models, do not support DVD-RAM.



Select a term to see the explanation