BEFORE buying any DVDs to use for copying of discovery, it is important to understand the capabilities and differences in DVD formats


What's the difference between + (plus), -(minus) and DVD-RAM format media?

Solution Currently there are many writeable and rewriteable formats on the market and it can be confusing to the average consumer. These formats include:

*         DVD-R

*         DVD-RW

•     +R

•     +RW


Almost all of the latest internal DVD writers now support the first four of these formats, and some of the latest support DVD-RAM recording also. The media you buy must suit your recorder's capabilities or it simply won't work.


DVD-R and DVD-RW - DVD-R and DVD-RW are both sanctioned formats of the DVD Forum, a consortium of companies involved in the development of DVD standards. Both formats generally use 4.7 GB discs. DVD-R is a write-once recordable format which allows excellent compatibility with both standalone DVD players and DVD-ROM drives.


DVD-RW media uses rewriteable discs which are rated for more than 1000 rewrites in ideal situations. The majority of standalone DVD players will play video recorded on DVD-RW discs, but the compatibility is not as high as with DVD-R.


Current DVD-RW recorders also record to DVD-R. However, the reverse is not always true. Some of the older DVD-R recorders are not capable of writing to DVD-RW discs (although some may be able to read DVD-RW discs burned with other drives).


DVD-RAM  -  DVD-RAM is a format originally aimed primarily as a data solution, but it is now becoming popular as a video format used by some brands of standalone (non-PC) DVD recorders (e.g. Panasonic). Current drives use 4.7 GB discs (or double-sided 9.4 GB discs).


DVD-RAM discs are traditionally housed within cartridges which cannot be opened, so that the media is well-protected. Newer Type II and Type IV cartridges can be opened however, an important feature for those who wish to read these discs in DVD-RAM compatible DVD-ROM drives or standalone DVD players. In addition, some DVD-RAM discs are now sold without cartridges.

DVD-RAM is a sanctioned format of the DVD Forum. DVD-RAM is a very robust data storage solution, theoretically allowing greater than 100000 rewrites per disc. In addition to support of the usual DVD UDF formats, DVD-RAM also allows fully integrated OS-level random read/write access similar to a hard drive, in both Windows XP (with FAT32) and Mac OS X (with FAT32 or HFS+), as well as on-the-fly write verification. The main drawback of the DVD-RAM format is its limited read compatibility by DVD-ROM drives and standalone DVD players. DVD-RAM read support with these units is increasing however.


+R and +RW  - These two formats are backed by the DVD+RW Alliance. While these formats are not sanctioned by the DVD Forum, several members of the DVD+RW Alliance are also members of the DVD Forum. Technically, “DVD” is not to be used in the names for these formats. since they are not approved by the DVD Forum. However, in reality, these discs are very similar to DVD-R and DVD-RW in design, usage, and compatibility.


+RW, like DVD-RW, is a rewriteable 4.7 GB format, and overall it has similar functionality to DVD-RW. One potential future advantage of the +RW format is the optional Mount Rainier drag-and-drop file access support (also known as +MRW) planned for future versions of Windows. However, current drives do not support Mount Rainier on +RW. The level of compatibility of +RW discs in standalone DVD players is similar to that of DVD-RW. The

rewritability of +RW is also said to be similar to that of DVD-RW.


+R is a format that was introduced to consumers in early 2002. It must be noted, however, that first generation +RW recorders did not support +R recording, and in most cases cannot be upgraded to do so. If one wishes to have +R burning functionality, one must purchase a recent drive specifically designed to do so. +R discs currently are somewhat more expensive than DVD-R discs, but prices will likely drop with time. Compatibility of +R discs in standalone DVD players is similar to that of DVD-R.


So what hardware should 1 buy then? (buy hardware) This is a very difficult question. The choice largely depends on one's usage environment and preferences.


DVD-RAM discs cannot be used in most standalone DVD players and DVD-ROM drives, and this has historically made this format less attractive for the average home user. However, the integrated OS-level drag-and-drop read/write data support of DVD-RAM makes it very attractive for some users, especially now that most current DVD-RAM burners also support DVD-R burning for video applications. DVD-RAM capable PC drives will also be ideal for those whom already own DVD-RAM based camcorders or standalone DVD-RAM recorders.

DVD-R/DVD-RW drives currently have the highest market penetration, both with PCs and Macs. As previously mentioned, DVD-R enjoys high compatibility with standalone DVD players. In addition, the low cost of DVD-RW is attractive to many for backup purposes (with the use of third party software and/or drivers). Furthermore, most standalone DVD players will read DVDRW as well, although the compatibility rate is significantly lower than with DVD-R.


+R and +RW are beginning to gain market share, and these discs appear to have similar compatibility on standalone DVD players as compared to DVD-R are DVD-RW, respectively. Current functionality with these drives is similar to DVD-R and DVD-RW drives, both for data and for video applications.


Can I use all of them?

As explained earlier, combinations of several of the formats are as standard with most modern drives. Pioneer's DVR-109 and the NEC ND-3500 are examples of writers that can burn to DVD-R, DVD-RW, +R and +RW.


Many of the newest range of drives have the functionality to record to DVD-RAM discs as well. These have been nicknamed 'Superdrives' by some because they are truly multi-format writers.


What about external DVD recorders?

Internal drives are cheaper but require you to open up the PC to fit them. There's an article on what's involved elsewhere in this knowledgebase. External drives are quicker to fit and involve less technical know-how. They are highly portable between machines.

Compatibility of external drives is not guaranteed With all software, however. Nero has support. You can adapt an internal drive for use as an external drive by buying one of our USB2 or Firewire external drive housings. As well as being portable, this solution has the advantage that it needs no free space in the host computer.