Difference between DVD+R and DVD-r

November 7, 2006 3:15 PM

What is the difference between DVD+R and DVD-R, from the standpoint of a casual computer user?

I do occasional DVD movie backups and burn backups of my HD to DVD. I've always used DVD+R but my wife recently got a pack of DVD-Rs (not RWs, just regular Rs) and I'm not sure what this means as far as I'm concerned. Is there any difference at all if I'm not using pre-2000 equipment?

Wikipedia didn't have anything on this, but it did link to a very technical essay on the difference, but it's way over my head.

All I want to do is back up movies and back up my HD. I don't know what issues I'll have mix/matching discs.

posted by calhound to Computers & Internet (14 answers total)

Differences to a casual user? None.
posted by unixrat at 3:17 PM on November 7, 2006

Some older DVD writers were only compatible with either DVD-R or DVD+R. Most writers these days do both.
posted by homer2k1 at 3:25 PM on November 7, 2006

Just to clarify, older writers could only do one or the other (not both).
posted by homer2k1 at 3:28 PM on November 7, 2006

Here's an article from About.com that talks about it. They start looking at the difference at the bottom of page one and onto page two.
posted by bwilms at 3:36 PM on November 7, 2006

DVD-R and DVD+R are actually different recordable formats backed by two different standards bodies; in essence, you can think of them as the late-90s equivalent of the Blu-Ray/HD-DVD split.

The reason why no one worries about -/+ the way they do now about BR/HD-DVD is because dual-format burners and players have existed for so long now that you basically can't find anything that does just one or the other. Each standards body will say they have their reasons for backing their format over the other guys' format, but by and large there's no actual difference in performance or capability across the board.

Where you might encounter some difference is with individual burners/players. Some Lite-On drives, for example, apparently burn DVD+R media better than DVD-R media. You'll have to read up on your specific drive to get an idea of which will perform better, though keep in mind that any performance difference will be relatively slight and, in most cases, not worth mentioning to the casual user.

Oh, and to add to homer2k1's point: older Macs will only recognize DVD-R media.
posted by chrominance at 3:47 PM on November 7, 2006

Some set-top box DVD players won't recognize DVD+R. Virtually all will be able to read DVD-R.

DVD+R is sometimes a little less expensive than -R media, but I always suggest shelling out the little extra cash and getting quality media regardless of + or -R.
posted by porpoise at 4:20 PM on November 7, 2006

porpoise - Some set-top box DVD players won't recognize DVD-R, but will recognize DVD+R. My fairly new, fairly expensive Sony is this way, while my 29.99 trutech will play both.
posted by Big_B at 4:25 PM on November 7, 2006

Check out videohelp.com's cheat sheet. For all practical purposes they are equivalent. According to their (rather extensive) compatibility database, -R works in 93% of set-top players, whereas +R only in 89%. You would be hard pressed to find a computer drive that could not read both equally. The -R holds slightly more data (4,706,074,624 bytes) compared to +R (4,700,372,992) but the difference is all but inconsequential.
posted by Rhomboid at 4:33 PM on November 7, 2006

Apparently the Superdrive in the new MacBook Pros supports regular DVD±R, but only supports writing to DVD+R DL (Dual Layer) media. I'd gladly be corrected on this though, as I've just ordered one!
posted by caek at 4:34 PM on November 7, 2006

It looks like that is true, but I find DL media to be ridiculously stupid. Hmm, let me see, burn two DVD-Rs at thirty cents each, or one DL disc for around two to three dollars. Or put another way, I've had a DL-capable burner now for years, and I have not used it once (not even a single time!) to burn DL.
posted by Rhomboid at 4:51 PM on November 7, 2006

Porpoise has got it right. When I was making some personal copies of DVDs, I experimented and found that my DVD player could read a DVD-R but not a DVD+R.
posted by Steven C. Den Beste at 5:46 PM on November 7, 2006

dvd-r reused the error correction scheme of cd's, whereas dvd+r improved on it.

Blank dvd's contain a tracker line and the burner align itself to that line. The tracker line also encodes infomation that let the burner measure how fast the disk is spinning, and how far along the track it has gone. One of the difference between dvd-r and dvd+r is, the encoding of that information on a dvd+r gives a higher signal-to-noise ratio. There are more differences of that kind.

In theory, dvd+r media will give you fewer burn errors. I read it on the net, so it must be true.
posted by gmarceau at 8:09 PM on November 7, 2006

caek, I read the specs on the macbook to mean that it can write to regular DVD±R as well as DVD+R DL. I'm entirely sure you will be able to write to either kind of single layer DVD, and the "+ only" only applies to DL media.

Hopefully I properly understood your concern! If you were just wondering about the +/- on DL, ignore me.
posted by flaterik at 8:11 PM on November 7, 2006

As an additional note, one reason why the Macbook might only support dual-layer burning with DVD+R DL media (and not DVD-R DL) is because the + coalition was the first to come out with their dual-layer burning standard, while the - coalition lagged behind. Now you know. (Cue G.I. Joe outro.)
posted by chrominance at 1:07 AM on November 9, 2006