Slashdot Mirror
CD Burners with Built in Compression
EconolineCrush writes "Bored of new CD-R/RW drives that only seem to decrease burn times by a few seconds over their predecessors? Check out this review of Plextor's PlexWriter Premium over at The Tech Report. With an advertised CD-R burn speed of 52X, the PlexWriter is certainly fast, but its ability to encrypt the contents of burned data CDs and squeeze nearly a Gigabyte of data onto a 700MB disc is what sets it apart from other high-speed burners."
Not only can we be pirates, but now we can be terrorists, all in one easy cd-burning step.
The Plextor's GigaRec feature uses shorter pit lengths to squeeze more data onto a disc. I guess in a way it is indeed a literal kind of compression. Still, the topic title seems somewhat misleading considering that the usual kind of compression people talk is about is something quite different.
A nice feature certainly, but of limited use. Those discs can only be read in that drive (and 1 or 2 older Plextor models). With current DVD-writer pricing who is gonna settle for a CD writer no matter how premium it is?
The "compression" used here is actually bending the CD spec, as the pits on the disc are smaller than normal. As stated in the article, no other drives were able to read the disc that had just under 1GB stored on the disc. The setting at 120% of normal capacity seemed to work on a few more drives, but still not all. Its prolly just easier to get a DVD+/-RWfor $300 USD instead of going and buying all new CD-ROMs/CDRWs that read the compressed discs (assuming you have a few computers).
The Doormat
If you're not outraged, then you're not paying attention.
Yes, because its a hardware "compression" technology, i.e. it doesn't modify the data it gets, just fits more of it on the disc: "The process works by shortening the length of the pits being written to the disc; shorter pits means more pits fit on the disc, and more pits means more data. The problem, of course, is that because these pits are shorter than the standard for data or audio CDs, compatibility with other drives may be hit or miss. Plextor does guarantee that the PlexWriter Premium will read any GigaRec disc, but they make no guarantees about other drives."
Just not at the same time.
GigaRec
The other special feature is GigaRec, which enables the PlexWriter to squeeze up to 40% more data than normal onto a piece of media. The process works by shortening the length of the pits being written to the disc; shorter pits means more pits fit on the disc, and more pits means more data. The problem, of course, is that because these pits are shorter than the standard for data or audio CDs, compatibility with other drives may be hit or miss. Plextor does guarantee that the PlexWriter Premium will read any GigaRec disc, but they make no guarantees about other drives.
So basically this will never catch on. The standard CD format is waaay to entrenched to be replaced. Other than for backup purposes, why would you want to burn a disc that's almost guaranteed not to work on another CD-ROM? The last thing need is another incompatible format of disc to worry about.. (DVD+RW, DVD-RW, DVD-RAM, etc)
SecuRec
Now that we've evaluated the drives' performance, let's take a look at a couple of the features that make the PlexWriter Premium so special. The first of these is SecuRec, which encrypts data before it is written onto the CD. You specify a password before beginning the write process, and once the CD is written, you need that password in order to view the recorded data. If the password is ever lost, so is the data.
There are a couple of limitations with the SecuRec feature. First, discs need to be recorded in DAO (disc-at-once) mode, so you can't burn multiple sessions of encrypted data, and as you might expect, only data CDs (not audio CDs) are supported. Second, in order to view the data, you need a copy of Plextor's SecuViewer software. This isn't that big a deal for Windows users, as the program is freely downloadable from the Plextor website. Linux and/or Mac users, however, are out of luck as far as I know, as SecuViewer isn't available for operating systems other than Windows. Just so there's no confusion, I'll point out that while you need a PlexWriter Premium drive to create a SecuRec disc, any CD-ROM drive can read one with the SecuViewer software and the proper password.
How this is better than a secure install program has got me... There's no real innovation here except that the encryption is moved to the CD Burning software. There are already quite a few tools to build installers that encrypt the installers and prompt for password to extract/install.
Basically it's just encrypting and then zipping except using a proprietary system....
Proprietary compression. Proprietary "encryption"? (They don't say enough to make a determination.)
I would typically use those features to archive sensitive information. And the when the drive breaks, or they stop supporting it, I'm hosed.
Thanks, but no thanks. I'll stick with standard compression/encryption tools.
You could just spend a little extra money on a DVD-R or DVD-RW drive, and gain the ability to burn 4.7GB of data to a disk that uses an already popular format.
Method 1:
mkisofs -z
From the manpage:
-z(Should not be too hard to port the transparent decompression code to *BSD and Darwin...)
Method 2:
KNOPPIX uses transparent decompression through a loop device to store more than 2 GBytes on a simple CDROM.
Just my two cents.
Denken hilft.
Just how many CD-ROM burners does this one count for?
One line blog. I hear that they're called Twitters now.
"squeeze nearly a Gigabyte of data onto a 700MB disc"
RIAA are gonna love this... "We found 5,000 burners - well actually we only found one, but it had 52x, compression and everything!"
CD-Rs degrade over time just like any other media. If you "compress" the data on it (i.e., use less of the media surface for each individual bit), it's more likely that a bit will become unreadable over time.
Suppose you're squeezing an extra 30% of data on the disc. I'd expect it's at least that much more likely that a scratch, excessive heat, time, or whatever would turn your backup into a coaster.
This is a bit different than the increase in HD platter density. With HDs, where the product includes both the rw mechanism and the media, the manufacturers had to implement stricter quality controls and test their media to tighter specs as they squeezed more data on the same amount of surface area. (And even still, reliability of IDE drives is poorer). In the case of these "compressed cds", the media is the same, and the manufacturers haven't tested its reliability when used with higher-density pits.
Maybe over time we'll see CD-R media that's been tested/certified for this standard (just like we now have media that's certified for various burn speeds). But until then I certainly wouldn't trust a compressed CD-R with any important data. (Or, I'd at least trust it far less than I do an uncompressed one)
I recently bought an rs232 plotter, a historic one, just because its manual had example source code for usage. The code was BASIC, but it was more than enough to get a plotter app written in Linux.
Before Bill Gates "0\/\/nz0r3d" a computer on every desktop in America, companies had to make stuff open. Before hard disks and resident operating systems were common, you had to release example code so that developers would make their software compatible with your hardware.
Now, many hardware manufacturers are only beginning to support alternative platforms again.
For the record, this thing's blatent violation of the CD-ROM standards would keep anyone with a brain from buying it. If these discs would work in all drives and the burner was worth the money, there would be Linux drivers within a few weeks.
For the company's sake, I hope they recoup their development costs. As for me, I have compatible cdroms, compressed ISO if I need it, and a tape drive whose capacity puts and disc to shame.
People won't sacrifice compatibility for a measly 44%. Well, I will with compressed ISO just because my backups will never be read outside a Linux system.
Did that article check the MD5 sums of the files? I suspect there was massive data corruption on the 3rd party drives.
You can't judge a book by the way it wears its hair.