Talk:DVD-RAM

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Error in First Line of Introduction[edit]

The first line of the article states that there are four competing DVD rewritable technologies, and then it specifies only three: DVD-RAM, DVD+RW, and DVD-RW. Would someone please clarify the article?

HI, WHICH OF THE 4 DVDs CAN BE BEST SUITED FOR CAMCORDER RECORDING & EDITING? 'CAN ANYONE HELP ESPECIALLY WHEN IT COMES TO EDITING? —Preceding unsigned comment added by 99.142.51.239 (talk) 21:11, 6 January 2008 (UTC)

A camcorder that uses solid-state storage. Apple8800 (talk) 08:43, 11 December 2010 (UTC)

Extinction of DVD-RAM[edit]

Is there any suspicion that the DVD-RAM format will be one of the formats 'lost' when the DVD shakeout ends? Similar to BetaMax and VHS in the early video tape recording saga.

It most certainly appears so. DVD-RAM is not as popular as it might have been, if you only consider the advantages. To most the disadvantages far overweigh those. Especially price. I mean, DVD-RAM costs 10-30 times more than a DVD±R and 5-10 times more than a DVD±RW. If one is to pay so much more, he better really need to put its features to good use. And few people care about that.
Probably not, DVD-RAM's are still made, they are not all that expensive. They are not 5 times more expensive if you know where to look. They have always had a niche market for professionals, they are only unpopular because in the good old days they required special hardware. With new drives being able to write to DVD-RAM as well as ordinary dvd formats it is the only optical drive that can be mounted as an ordinary removable drive, without any special tricks
DVD-RAM may be running last-place in the computer community, but since Panasonic (for one that I know of) has chosen DVD-RAM for all of its DVD recorders it appears that DVD-RAM will be getting some significant new sales volume. This should drive down the manufacturing cost and drive further adoption in both the video and computer communities.

DVD-RAM is to quite a big extent dead, it has mainly been replaced by less capable formats, in the form of Plus and Minus, although it has established itself a market in the 8cm Camcorder disc, but overall this capable format of disc is dead. 172.142.243.19 (talk) 09:27, 15 February 2008 (UTC)

It still has some uses where money plays no role. For example IBM System z mainframes can use DVD-RAM ( for example the z/VM evaluation is a DVD-RAM and if I remember correctly the other OS can be shipped on DVD-RAM - if you do not want tape/ etc ) —Preceding unsigned comment added by 84.161.49.1 (talk) 17:26, 23 April 2009 (UTC)
In the deepest, darkest reaches of tech and video, where white labcoats are still worn, I see DVD-RAM as the de facto medium for storage between computers. TV station I worked at also used DVD-RAM in all live video capture, and have huge shelves full of just DVD-RAM. And I've worked at other TV stations that still use Betacam. Apple8800 (talk) 08:45, 11 December 2010 (UTC)

Capacity[edit]

Requesting an update from somebody who knows about this for sure: why does the capacity drop to less than 4.7GB after formatting, and is this a source of confusion.

Yes, the abreviations of G (billions) usually take a different meaning when applied to bytes, in wich case they are based on powers of 2 instead of powers of 10. Common use Gig, like in SI, are 10 power9, but computuer Gig is 2 power30. (2 because there is 2 options 0 or 1). So 4.7 GB is in fact 4.38 computer GB.

I think the original question refers to something else. As far as I know, an unformatted DVD-RAM can be recorded to using any burning software, and it will hold the same amount of space than a DVD±R/RW, i.e 4.7GB or 4.38GB, depending on how you count. A formatted DVD-RAM will hold noticeably less, some 200MB less. Sure you'd expect some overhead for the file allocation table, but not this huge. I'm not entirely sure what the cause is, but I've been explained that it's space that is being put aside for sector defect management.
look up the difference between GB and GiB. Then learn how to sign your comments by placing three or four tildes at the end of your post. :) Don't give an Ameriflag 03:29, 9 May 2006 (UTC)
Ignore the rude comment above. Anonymous comments are perfectly acceptable.
This drop of capacity is indeed due to the Defect Management implemented in DVD-RAM. There is one "Primary Spare Area" at the beginning of the disk that is reserved and contains spare sectors to replace defective ones that are found during the usage of the disk. On 4.7 GiB disks, this area contains 12'800 sectors (= 26'114'400 bytes). There can be a "Supplementary Spare Area" at the end of the disk that can be up to 12'517'376 sectors (= 200'278'016 bytes). Both together make 226'492'416 bytes or 216 MiB. Note that replacements are done by blocks of 16 sectors at once (the size of an ECC Block). Nothing to do with the difference between GB and GiB... --Evoisard (talk) 17:11, 7 December 2007 (UTC)

Compatibility[edit]

The DVD-RW page says that DVD-RWs are compatible in 75% of the world's DVD players, unlike DVD-RAM. What is the compatibility rate for DVD-RAM?

None. DVD-RAM's only work in DVD-RAM systems, as they make no attempts to emulate the older systems. DVD-RW discs try to be 'normal' DVD's, so thats why they get 75% compatibility. But no non DVD-RAM system can read a DVD-RAM disc. --Kiand 02:17, 3 Jun 2005 (UTC)
Incorrect -- DVD RAM disks are readable by the following types of drives: DVD-RAM, DVD-RAM(R), DVD-Multi, DVD-ROM, and DVD-Video. They are writable by the first three. Source: Maxell (www.maxell.com or 800-377-5887). Example: from the back of a package, "After recording, this DVD-RAM disk can be played back in DVD-RAM compatible drives, video recorders and DVD-ROM/DVD-Video players."


Some multi-format drives claim to read DVD-RAM (such as the Pioneer DVR-109 and this Panasonic player.) But DVD-RAM is unlikely to work on older players, or anything that doesn't specifically support it. --Synchrite 04:53, 2005 Jun 3 (UTC)

DVD-RAM DL?[edit]

Will there ever be DVD-RAM Dual Layer -technology? Henri Tapani Heinonen 16:53, 5 Jun 2005 (UTC)

Anyone? Henri Tapani Heinonen 08:10, 2 August 2005 (UTC)
No. There will likely by +RW DL at the end of the year, though. But there are no plans that I know of for -RAM DL, and I have a feeling that the format will not be very permissive of such.
Sad. :( Henri Tapani Heinonen 09:43, 2 August 2005 (UTC)
Do you mean as a flipper disc, or like a one-sided disc? I've used 9.4 GB flippers for years at the TV station I worked at. However, I must admit, while 8.5 GB would be nice to have on both sides of a DVD-RAM disc, SSDs are easier to use in this function. So, I agree, I doubt there's going to be development of a DVD-RAM DL. Plus, most uses of DVD-RAM seems to be the data sector, I mean like labcoats data sector, so data is the primary, uh, data for DVD-RAM storage. Apple8800 (talk) 08:49, 11 December 2010 (UTC)
I meant one-sided, two-layer discs, a bit like DVD-R DL. Urvabara (talk) 11:04, 7 July 2011 (UTC)

No special software required?[edit]

(From main page) "Unlike the competing formats DVD+R, DVD-R, DVD+RW and DVD-RW, you do not need special DVD burning software to write or read DVD-RAMs on a computer. DVD-RAMs can be accessed like a usual floppy disk or hard drive". "No DVD burning software required in computers – discs can be used and accessed like a removable hard disk; MS Windows requires a special DVDRAM driver or InCD program, although Windows XP can write to FAT32 formatted discs directly."

I found this confusing. The 2nd sentence seems to contradict the 1st one (IMO a special driver *is* DVD burning software) at least for MS Windows. And XP also comes with built-in support for burning to standard CDs (and so, I'd assume DVDs?): hence I'd see XPs support of DVD-RAM as being due to XP having had an InCD-like driver added, rather than of any property of DVD-RAM (AFAIK XP licenced some burning api off some company, and the next version of windows will licence something from http://www.sonic.com/). Also the article in general implies I could unplug a HDD, plug in a DVD-RAM, and to my operating system they'd appear the same. AFAIK this is not the case - if the OS has support built into it, then *to the user* they may appear the same, but the hardware interface itself *is* different (http://groups.google.co.uk/group/microsoft.public.windowsce/browse_thread/thread/11e2b0f13bd2f1ad/15518136cbf6e170?lnk=st&q=dvd+ram+windows+ce&rnum=2&hl=en#15518136cbf6e170). Hence I'd assume in other OSs support is prebuilt into them, rather than no additional support over that for a HDD being required.

I don't feel confident enough to edit the article itself (this is not my field but I have been looking into it for work) but I thought I'd raise it for discussion in the hope that someone who knows will edit it if editing is required.

New DVD-rams used in external dvd-ram drives must be formated before use (FAT 32), right click the drive and click format,no indication that the ram is being formated will be seen until (format complete) pops up.Turn off (Allow CD burning) in the properties of the drive.DVD-Rams can be used as ordinary DVDs.A ram burnt as a normal DVD or before formating MUST be erased or reformated to use as a ram again.No special software is required with XP.

Comment - actually this is only true for Windows, which has very poor support for drives in general. In Linux has built-in suppport for a multitude of file systems and you can choose from several for use on DVD-RAMs. Same goes for MacOS (although HFS+ is the default). Use of these drives is highly transparent on either of those operating systems - not the struggle it is with Windows.
The way I understand the "no software required and can be used just like a hard-drive or a floppy" is that it applies, provided that the correct driver is installed. It's not the same driver that is used to recognize and access HDs and floppies, that's true, because the hardware IS different. But with the driver, the user can access DVD-RAM just like a hard disk, a floppy or a flash disk - one can read and write using the standard OS routines, without loading some application like Nero or Roxio.
So what? A driver is software. This seems like a completely meaningless distinction. You can't use the drive without the driver, so how is that a lack of "special software"? Who cares (aside from the software developers) what exactly is going on inside of the software or which pieces of the software are doing what? —Pangolin 16:18, 3 September 2006 (UTC)

The article states that DVD-RAM is directly supported by Mac OS 8.6-9.2, but not by Mac OS X. But I plugged an LG DVD-RAM drive into my Power Mac G5 running OS X 10.3, was able to format it as HFS+ using the OS's disk utility, and use it. It just worked! Please explain how Mac OS X does not support DVD-RAM! - Paul Oct. 22, 2007.

RAM or no RAM[edit]

I'm curious about this particular sentence in the article:

The term DVD-RAM is a misnomer; the name is based on the (erroneous) abbreviation for RAM, meaning "read-and-write memory" - the opposite of ROM (Read-Only Memory). However, RAM actually stands for Random Access Memory (computer chips) and DVDs inherently cannot use the random access method.

What does the writer mean by "DVDs inherently cannot use the random access method"? The way I understood it, DVD-RAM differs from regular RW media in the sense that it really does allow random access writing, in the sense that you can change a single byte in a single file, just like you can on a floppy, without having to erase and rewrite sequentially, as is the case with regular RW media. Is that not random access in its true sense? How is it different from floppies or hard disk? I'm eagerly waiting for comments and explanations.

I have no idea if indeed DVD-ram are random-access as in the change-single-byte thing, but when I read it I was assuming the contributor was talking about the relative speed of optical vs. hard drives in general. If you have a full DVD of any type, it's gonna take a few seconds to go from the inside of the disk to the outside, but I doubt the same would be true of a hard drive. --68.210.95.54 11:45, 1 July 2006 (UTC)

All DVD types allow random access. No DVD (or harddrive or floppy) allows changing a single byte. xerces8 --90.157.129.176 13:27, 21 January 2007 (UTC)

Not correct. DVD+RW specifically supports byte accurate access for both read and write. DVD-RW does not - that's the practical difference. DVD-RAM does not support byte accurate access on the disc itself, but like hard discs and floppy discs a byta can be changed by reading the whole sector; making the required change and then writing it back. Incidentally, BD-RE contains the DVD+RW technology whereas HDDVD-RW does not. 86.178.9.171 (talk) 17:05, 24 September 2010 (UTC)

Access times for any optical media is absolutely horrible when compared to all other storage mediums. It's on the order of milliseconds due to the mechanical parts. True random-access mediums (such as RAM) are on the order of 5-10 ns. Thus random single-byte reads on optical media is not really feasible. DVD's and CD's, like the old record players they replace are built for sequential reads and writes, this is why the gentlemen above states that it is inherently a non-random access method. Yes, technically you can do it, but it is utterly too slow to be considered.

Well. DVD-RAM's are formatted like hard disks - in sectors that can be accessed in a random manner. Other DVD formats are like old vinyl discs or CD disks - data is in a long spiral. See e.g. http://www.optodisc.com/q&a.html. "RAM" does not refer to speed but the way the memory access is arranged. —Preceding unsigned comment added by 82.181.181.176 (talk) 20:45, 5 November 2007 (UTC)

It is not exact to say DVD-RAM are formatted like hard-disks, and the sentence "The on-disc structure of DVD-RAMs is closely related to hard disk and floppy disk technology, as it stores data in concentric tracks" in the article is wrong. In a DVD-RAM, data is in a long spiral, like in other DVDs, but it's divided into sectors (that can be accessed randomly for read or write operations, like RAM). From the ECMA-330 Standard, chapter 14.1: "Each Track shall form a 360° turn of a continuous spiral", from ECMA-330 Standard, chapter 14.2: "The Track Path shall be a continuous spiral from the inside (beginning of the Lead-In Zone) to the outside (end of the Lead-Out Zone) of the disk."--Evoisard (talk) 17:02, 6 December 2007 (UTC)
DVD-RAM does not use a spiral track. The tracks are annular, just like on a hard disc. The reference you used applies to single layer conventional DVD media only. 86.178.9.171 (talk) 17:05, 24 September 2010 (UTC)

The myth of DVD-RAM's data can be retained long[edit]

"Long life — without physical damage, data is retained for 30 years minimum."

I wonder if it is just a theoretical claim. There're some theoretical claims about the lifespans of different DVDs:
- Expected longevity of dye-based DVD-R and DVD+R discs is anywhere from 20 to 250 years
- The phase-change erasable formats (DVD-RAM, DVD-RW, and DVD+RW) have an expected lifetime of 25 to 100 years.

However some evidence shows the claims may be wrong. Some DVD discs may go off just after a few years or even less.

 DVD-RAM has been around for somewhat less than thirty years so time travel notwithstanding the data is theoretical.
I had a DVD-RAM disc that kept the data from 1998 till it's destruction by sitting on it by accident in 2006. I never formatted it, and used a particular program to write to it, though, 'til I got a Mac with OS X. That's my personal experience. I do have DVD-RAM discs from 2000 to the present that have also retained data. So, what are you getting after? Apple8800 (talk) 08:52, 11 December 2010 (UTC)arsim azizi

Disadvantages of DVD-RAM[edit]

I removed the following from the article:

The statement is true, but we should be comparing DVD-RAM to other types of DVD media, not to hard disks, or video cards, or pregnancy pills.

 If you are considering using DVD-RAM as additional primary storage you should consider the overall performance compared to other types of storage. I agree however that a comparison of access time is not much use.

VR mode recording mode[edit]

The article uses this phrase several times without defining it. It might be that 'VR' stands for "video recording", but I'm not sure what that has to do with DVD+-RW... and if so, the phrase is doubly redundant: 'video recording mode recording mode'?! So it needs to be explained the first time it's used, or if it's that redundant thing it should get cleaned up. 70.231.133.38 14:07, 17 February 2007 (UTC)

packaging + drives[edit]

Its not clear whether DVD-RAMs are played in their cartridges or have to be removed from these out of these to do so. Are drives that support them specially constructed to accept the cartridges (or bare disks)?--ChrisJMoor 19:04, 25 March 2007 (UTC)

Just found a small part of the article that mentions this, but it should be more prominent and better explained because the cartridge represents a significant departure from the bare disk format of CDs and DVDs

I believe that initially cartridges were required for the early players, which is part of the reason that dvd-ram never caught on (discs were too expensive to purchase). Newer recorders do not have this restriction.

It will always be better to use cartridge DVD-RAMs than cheaper bare ones, especially if you want to use them for numerous writes/reads, what DVD-RAM is designed for. The reason is that any dust particle or finger print across one or more sectors will cause them to be marked as defect and spare ones to be used at their place. The amount of spare sectors is limited, and the necessity for the drive's head to jump back and forth from the main user area to the spare zones will lower the drive's performance, and lifetime. Cartridge recorders can work with bare optical disks too. --Evoisard (talk) 09:53, 10 December 2007 (UTC)

Misunderstandable part in article?[edit]

"It is even possible to use the ext3 file system on a DVD-RAM disc. " - This sentence comes after a sentence about MacOS, but I think it refers to the Linux part two sentences earlier. Anyone to verify in the edit history or with a citation? --132.231.54.1 19:57, 12 April 2007 (UTC)

Why is a cartridge needed?[edit]

Just curious as to why a cartridge is needed (or even offered) with DVD-RAM, but not with other media such as CD-RW/DVD+-RW ?

Davez621 (talk) 12:00, 25 January 2008 (UTC)

Probably because early DVD-RAMs weren't very scratch resistant. DVD-RAM is also incompatible with other DVD discs so it was pretty easy to develop a cartridge for DVD-RAM, because non-DVD-RAM-drives cannot read the DVD-RAM even if it didn't have the cartridge. Urvabara (talk) 08:29, 12 August 2008 (UTC)

I can remember around the year 2000 we had a system at my school with a drive that only took cartridges. To load a CD/DVD you would need to put it inside a cartridge and load it. Newer DVD-RAM discs (notably verbatim) have a hard coat that is very scratch resistant, much like BD discs have. 98.221.227.111 (talk) 19:52, 2 April 2012 (UTC)

What is DVD-RAM2?[edit]

I do not understand. What is DVD-RAM2? There is already DVD-RAM version 2.x. Can you put some info about DVD-RAM2 to the main article? Urvabara (talk) 17:46, 27 February 2008 (UTC) dtc meni

Spare Area[edit]

Ist this Spare Area only used when UDF formated or is it used trasparently internal of the device for any filesystem?

Extinction update - no new media[edit]

After suffering three DVD-R data coasters for whatever reason, I remembered I had some DVD-RAM from 2006, and I read about the format. Seems cool...the disc worked, and I have Panasonic 2-3x discs. Supposedly there should be 5x, 6x, 8x, and 12x discs and I thought for a second, "Wow, this is cool and I can buy a new faster disc for backups."

Not so - 5x discs are almost unavailable and as far I see, development on DVD-RAM ended in 2004 with the release of the 5x discs by Maxell and Panasonic. All you can buy anywhere are 10 year old packages of 3x discs. The low low price of solid state storage and high cost of DVD-RAM means that this format has been abandoned.

Optical drives in general have been slow and less than fully reliable storage, only the physical distribution of movies and software on discs prevents the whole technology from being abandoned.76.105.131.18 (talk) 02:26, 1 October 2015 (UTC)