dbminter Posted March 19, 2021 Posted March 19, 2021 I think I've asked this before. If I have, my apologies for asking it again. Which has more available recording space? DVD-R or DVD+R? Which has more available recording space? DVD-RW or DVD+RW? Thanks!
Ken852 Posted March 20, 2021 Posted March 20, 2021 Coincidentally, it just so happens that I found the answer to your second question purely by tedious experimentation (no googling). The answer is DVD+RW. Evidence is presented below. Disc name Disc size Disc type ================================================= Backup 01 - 2009-11-04 4,700,372,992 DVD+RW Backup 02 - 2009-11-04 4,700,372,992 DVD+RW Backup 03 - 2009-11-04 4,700,372,992 DVD+RW Backup 04 - 2009-11-04 4,700,372,992 DVD+RW Backup 05 - 2009-11-04 4,700,372,992 DVD+RW Backup 06 - 2009-11-04 4,700,372,992 DVD+RW Backup 07 - 2009-11-04 4,700,372,992 DVD+RW Backup 08 - 2009-11-04 4,700,372,992 DVD+RW Backup 09 - 2009-11-04 4,700,372,992 DVD+RW Backup 10 - 2009-11-04 4,700,372,992 DVD+RW Backup 11 - 2009-11-04 4,700,372,992 DVD+RW Backup 12 - 2009-11-04 4,700,372,992 DVD+RW Backup 13 - 2009-11-04 4,700,372,992 DVD+RW Backup 14 - 2009-11-04 4,694,933,504 DVD-RW Backup 15 - 2009-11-04 4,694,933,504 DVD-RW Backup 16 - 2009-11-04 4,694,933,504 DVD-RW Backup 17 - 2009-11-04 4,694,933,504 DVD-RW Backup 18 - 2009-11-04 4,694,933,504 DVD-RW Backup 19 - 2009-11-04 4,694,933,504 DVD-RW Backup 20 - 2009-11-04 4,694,933,504 DVD-RW Backup 21 - 2009-11-04 4,694,933,504 DVD-RW Backup 22 - 2009-11-04 4,694,933,504 DVD-RW Backup 23 - 2009-11-04 4,694,933,504 DVD-RW Backup 24 - 2009-11-04 4,694,933,504 DVD-RW Backup 25 - 2009-11-04 4,694,933,504 DVD-RW Backup 26 - 2009-11-04 4,694,933,504 DVD-RW Backup 27 - 2009-11-04 3,240,558,592 DVD-RW What you see is a list of DVD discs containing a 116 GiB (125,379,543,040 byte) backup archive that I split across evenly on 27 DVD discs 12 years ago. The discs I used were Philips I believe (DVD+RW) and from the looks of it I must have run out of those so I switched to Verbatim (DVD-RW). This was a one day job, as you can see by the dates. You will notice that each of the first 13 discs is 4,700,372,992 bytes. Those are the DVD+RW discs. Once I switch over to DVD-RW this number changes to 4,694,933,504 bytes. (The last disc contains only the remaining data that did not fit on the previous discs.) This was a surprising find, because I had no idea that there was any such difference between DVD-RW and DVD+RW. I take it that this is why the latter has a plus ("+") symbol in the name? I really never knew in what way those "plus" discs were different from regular discs without the plus when they first appeared, I never cared, because they served me equally well as the other, "regular" discs without the plus symbol. I hope this answers your question. I have not googled this yet (still). I might be wrong. I noticed that there is about 11 MiB unused or free space on each disc. I can't tell if it was exactly the same number for both DVD-RW and DVD+RW. Perhaps this is a reserved space that can't be written to? I don't know. I did not do the splitting myself, a program did that for me, back in the day. But seeing is believing, and I believe DVD+RW will fit more data than a DVD-RW. So it only seems reasonable to assume that the same applies to DVD+R vs. DVD-R.
dbminter Posted March 20, 2021 Author Posted March 20, 2021 I had it in mind that DVD+RW was larger than DVD-RW. The reason for the + is because the name DVD-R was already taken, being the first DVD WORM recordable media. When the consortium created their format, they simply chose DVD+R as the name because it made sense to go from minus to plus. Another advantage of DVD+RW over DVD-RW is the erasure of that media is nearly instantaneous. There's a lead in time for erasing DVD-RW that takes about a minute. Another advantage of DVD+RW, I think, is its Writing LeadIn time is shorter than DVD-RW's. Another is I think DVD-RW only reached 6x max write speed whereas DVD+RW reached 8x. There is an advantage of using DVD-R over DVD+R when making DVD Video discs. Since DVD-R is the older format, older DVD players that don't play DVD+R have a better likelihood of playing DVD-R. DVD-R is more compatible with DVD players because it's an older format.
LIGHTNING UK! Posted March 21, 2021 Posted March 21, 2021 DVD-R holds more. Same for DVD-RW. As taken from the Media Testing section of the forum... DVD-R Free Sectors: 2,298,496 DVD+R Free Sectors: 2,295,104 DVD-RW Free Sectors: 2,298,496 DVD+RW Free Sectors: 2,295,104
Ken852 Posted March 21, 2021 Posted March 21, 2021 (edited) DVD-R: Verbatim 16x DVD-R [MCC 03RG20] Free Sectors: 2,298,496 Free Space: 4,707,319,808 bytes https://forum.imgburn.com/index.php?/topic/600-verbatim-16x-dvd-r-mcc-03rg20/ DVD+R: Verbatim 16x DVD+R [MCC-004-00] Free Sectors: 2,295,104 Free Space: 4,700,372,992 bytes https://forum.imgburn.com/index.php?/topic/542-verbatim-16x-dvdr-mcc-004-00/ DVD-RW: Verbatim 4x DVD-RW [MCC 01RW4X] Free Sectors: 2,298,496 Free Space: 4,707,319,808 bytes https://forum.imgburn.com/index.php?/topic/3087-verbatim-4x-dvd-rw-mcc-01rw4x/ DVD+RW: Verbatim 4x DVD+RW [MKM-A02-00] Free Sectors: 2,295,104 Free Space: 4,700,372,992 bytes https://forum.imgburn.com/index.php?/topic/603-verbatim-4x-dvdrw-mkm-a02-00/ For brand comparison... BEST 16x DVD+R [BeAll000-PG0-00] Free Sectors: 2,295,104 Free Space: 4,700,372,992 bytes https://forum.imgburn.com/index.php?/topic/3116-best-16x-dvdr-beall000-pg0-00/ Edited March 21, 2021 by Ken852
Ken852 Posted March 21, 2021 Posted March 21, 2021 Indeed, according to the tests that users have done and posted on this forum, both DVD-R and DVD-RW can hold more data (4,707,319,808 bytes) than DVD+R and DVD+RW (4,700,372,992 bytes). I referenced a "BEST 16x DVD+R" disc for sake of comparing another brand to Verbatim. This is a very limited sample of course but it indicated that there are no deviations between brands in terms of available storage space. Of course, I remember those kind of tests mainly being done for sake of testing the quality of the discs. I just wanted to see for myself that different brands report same storage space. But it sounds to me like DVD+RW is the more advanced and preferable choice over DVD-RW when it comes to RW discs. So it would seem wise to get DVD+RW for RW discs (for the advantages listed previously) and DVD-R for R discs (can store more data). Both DVD-R and DVD+R are preferable for data longevity.
Ken852 Posted March 21, 2021 Posted March 21, 2021 What puzzles me now is why the DVD-RW discs in my backup archive above cut off at 4,694,933,504 bytes, 5 MiB less than that of DVD+RW (4,700,372,992 bytes) when according to the numbers above, DVD-RW discs can fit 6 MiB more than DVD+RW discs (note less). At any rate, I should be able to fit 4,700,372,992 bytes regardless if I use DVD-RW or DVD+RW. The DVD+RW discs are filled to the brim, but not DVD-RW discs. Any explanation for this?
LIGHTNING UK! Posted March 21, 2021 Posted March 21, 2021 Were you using the same drive you're having issues with in one of your threads? Beyond that, I've no idea.
Ken852 Posted March 21, 2021 Posted March 21, 2021 (edited) No, those were written with a PATA drive, the NEC ND-3520A. I currently use a Samsung SH-224DB SATA drive. I think I used something like 7-Zip or "PeaZip" (same thing, different face) for splitting. So it's a 7-Zip archive. So I should be able to max out DVD-RW discs at 4,707 ,319,808 bytes? There is no overhead involved or something like that? Edited March 21, 2021 by Ken852
LIGHTNING UK! Posted March 21, 2021 Posted March 21, 2021 There’s overhead of the file system(s) you decide to use on the disc.
Ken852 Posted March 21, 2021 Posted March 21, 2021 (edited) I think UDF 1.02 was used. But that overhead should be equal on both DVD-RW and DVD+RW? I have not found any specifics about the UDF overhead on DVD discs, but this bit about CD discs is quite interesting: Quote The so-called UDF overhead that is spread over the entire disc reserves a portion of the data storage space, limiting the useable capacity of CD-RW with e.g. 650 MB of original capacity to around 500 MB. https://en.wikipedia.org/wiki/Universal_Disk_Format#Spared_(RW)_build I am speculating, but it would seem as if UDF is not the ideal choice if you want to max out the capacity of a DVD-RW disc. This is somewhat related and an interesting question on how to predict the overhead size in UDF formatted discs (or UDF "images" rather): https://superuser.com/questions/1224637/calculating-expected-overhead-in-udf-filesystem Edited March 21, 2021 by Ken852
dbminter Posted March 21, 2021 Author Posted March 21, 2021 I'm not certain, but since it says Spared in the link, I wonder if that means when a disc is formatted with spare areas. That would reduce the available space for writing.
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