Basics about DVD

What is -R,+R,-RW,+RW? What is a multisession? Is -R a DVD that once you wrote something on it you can never erase it or write over it but you can only add to it if you have space on the DVD??

A lot of this stuff, and in-depth explanations, can be found if you search the Blank Media forum. :slight_smile:

Here’s just a quick recap, as I understand it (so it’s subject to correction by other members!) -

-R and +R are write once media - i.e. you can only write to them once, and you can’t erase what you’ve written.

If you burn a multi-session disc, you can write stuff to it in seperate sessions, using an appropriate burning app (Nero, for example).

-RW and +RW - you can write to, then erase, then write to these discs more than once. How long they last is a matter of personal experience, and has been discussed quite a bit on here (in fact, there’s a thread on this very page).

For the difference between + and -, have a look at the Sticky thread in this section. :wink:

Most modern burners are multinorm burners, and will support +R, -R, +RW, -RW and some will even support DVD-RAM. DVD-RAM is a special rewritable format which is sectored and supports packet writing natively, so you can use DVD-RAM like you use a hard disk and without burning, if your drive supports it.

While +R and -R are based on organic dyes (cyanine and azo), +RW, -RW and -RAM are phase-change. Both have its advantages and disadvantages, the R media is more sensitive to light while the RW media will give you higher PIE/PIF error rates and is generally not as good. DVD-RAM is a head above the rest, because it will survive up to 100,000 rewrite cycles (unlike [U]properly manufactured[/U] RW’s 1,000 cycles), making it almost as capable as a flash key.

You should not burn Multisession unless you really want to use it. For example, a full disc should always have a closed session.

There’s lots of other stuff… :wink:

Thank you both very much for this info. I just wanted to ask arachne one question about multi session. What are the disadvantages of multisession (I understand that I should not perform multisession). I need to know too how to close the DVD with Nero (Nero Start Smart (Nero- I burnt some PS2 game and it does not work … may be cuz I did not close the DVD. I keep writing to it and it accepts; I think this means that it is still open.

To close a DVD, put the disc in, and start up the main Nero app. Go to
Recorder -> Disc Info. In the bottom left, should be a button that says “DVD R Options”.

Hit that button, and if the disc is still open, it should give you a “Close Disc” option. Click that. I’m still using, so the option may be a little different for you.

And for disadvantages…I don’t really use RW, or multi-session, but the only one I can think of, is that regular players etc might not be able to “see” anything other than the first session on the disc.

This is just a guess, as I say, I don’t really use them. :slight_smile:

Just a couple additions to the above that spring to mind:

  • for every session you add you lose about 50MB I believe (more important for CD-RW obviously)
  • you’ll want to burn that game in one closed session (look through all the options before hitting Burn - I can’t check it right now, but you can definitely select to close the disc [I]before[/I] you start the burn process)

Yeah, there’s a checkbox for that in the Burn window, IIRC (“finalize disc” or something?) :iagree:

I know absolutely nothing about backing up games :bigsmile:

Neither do I, Arachne :flower: . Just think that anything you [I]copy[/I] should be closed, as is the original.

The amount you lose per extra session depends on the disc format.

For DVD-R(W) you lose 32-96 MB for the first added session, and for subsequent sessions you lose 6-18 MB.

For DVD+R(W) you lose 2 MB for every added session, but for DVD+RW it’s also possible to allocate all the space at once, and then use only some of that allocated space and save the rest for a later session.

For more about this read this article on DVD+R vs DVD-R.


For CD-R(W) you lose 22 MB for the first session and 13 MB for each subsequent session.
Source: Roxio - All About Multisession.

Hehe, good point! I think I set mine to “No multisession” and the “Finalize Disc” box always seems to be already checked, so it’s not something I think about often :bigsmile:

Yeah, if you do a straight “Copy Entire Disc” (or whatever it’s called) it’s not even an option, I think.

Thanks for the clarification, DrageMester.

Thank you so much guys. This is a lot of info…!!!

This is not important for always-erasable CD-RW. It is only important for CD-R. :wink:

Just never use multisession if it’s not needed and everything should be fine :smiley:

Like with CD, only adding the 2nd session need that amount of space for data management. Further sessions don’t need such an large amount of space…