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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sunday 22 December 2002 8:51 pm, Tom Glare wrote:
Have just tried using one of these devices for the first time, and it appears to be first time lucky, as the resulting CD seems to be just fine. But there are a couple of things that perhaps the expert
As it should be!
"burners" out there may be able to answer. First, speed : I thought I had a drive that would write at twelve times something, though I'm not sure what that something is, and come to that I wouldn't put my shirt on the twelve either, as the device didn't come with a manual. Anway, "speed=12" was specified, and among the abundance of information that "cdrecord" spat out, was the following ..
The various speeds are normally part of the name of the drive: Identifikation : 'LTR-40125S ' 40 speed write, 12 speed re-write. So this drive will write a CD-R (write once, read many times disc) at 40 speed. This equates to 40 times faster than the disc would be read by a standard music CD player. A CD-RW disc requires a lower writing speed, so those more expensive write many, read many discs can be written at 12speed. (I've only got older CD-RW discs with a max of 2speed though so haven't tested that.) As a normal music CD is upto an hour of music, 2speed will take 30 minutes to write the data (not including the lead in and lead out times) and a 20x speed will take 3 minutes. My 40x generally gives a write time of ~90-120 seconds for the complete write, including lead in and lead out. (These are the points when the laser is writing blank data that signifies the end and beginning of tracks (I think.)) Try using cdrecord -prcap It makes a (longer) more intelligible output: [neil@xxxxxxxx neil]$ cdrecord -prcap Cdrecord 1.10 (i586-mandrake-linux-gnu) Copyright (C) 1995-2001 Jörg Schilling scsidev: '0,0,0' scsibus: 0 target: 0 lun: 0 Linux sg driver version: 3.1.20 Using libscg version 'schily-0.5' Device type : Removable CD-ROM Version : 0 Response Format: 2 Capabilities : Vendor_info : 'LITE-ON ' Identifikation : 'LTR-40125S ' Revision : 'ZS0N' Device seems to be: Generic mmc CD-RW. Drive capabilities, per page 2A: Does read CD-R media Does write CD-R media Does read CD-RW media Does write CD-RW media Does not read DVD-ROM media Does not read DVD-R media Does not write DVD-R media Does not read DVD-RAM media Does not write DVD-RAM media Does support test writing <snip> Here's the stuff you wanted: Maximum read speed in kB/s: 1408 Current read speed in kB/s: 1408 Maximum write speed in kB/s: 7040 Current write speed in kB/s: 7040 Buffer size in KB: 2048 Not sure how those calculations work out, perhaps the read speed is actually the erasable speed?
Identification : LTR-12101B Revision : LUS3 . . ATIP info from disk : Indicated writing power : 5 Reference speed : 2 Is not unrestricted Is erasable
This could be part of the reason why cdrecord is putting out the extra data - you are using an erasable disc CD-RW. CD-R's will write faster.
ATIP start of lead in -12900 (97:10/00) STIP start of lead out 359849 (79:59/74) Speed low: 0 speed high : 4 Power mult factor: 4 5 Recommended erase/write power: 3
That's the recommended erase/write speed OF THE CD-RW DISC, not the writer. Your 12speed drive may well be a 12x4 drive, 12speed CD-R, 4speed CD-RW. That would fit with other, slower, drives I've had previously. The erasable speed of the drive is often a third of the non-erasable speed. In this case, the drive wrote the disc at higher than the recommended speed for the disc.
A2 values : 5C C6 26 . . (at end of process) Average write speed 4.0x So which of these figures, if any, do I have to take notice of, and does it matter what speed I put in the "cdrecord" line ? The overall cooking
Yes it does matter what speed you put on the command line, but the drive simply cannot write faster than the maximum for the operation. In this case, it found an erasable disc and had to write at the slower speed.
time (for 650MB of data) was twenty minutes. Is this about normal ? Am I
20 minutes - that includes lead in and lead out so say 16mins for the data, that's about 4speed, as reported. Use a CD-R disc (non-erasable) and you could get to the 12speed and cut that total time to under 7 minutes.
right in thinking that if I use one of those "once burnt, twice shy" disks it would be quicker ?
A lot. In this case, three times faster.
Finally, is the following information (which again was part of the "cdrecord" output) recognizable to anyone ... "Manufacturer : unknown (not in table) Manufacturer is unknown because of the orange forum embargo. As the orange forum likes to get money for recent information, it may be that this media does not use illegal manufacturer coding." Well, absolutely. Good thing too. Erm, what exactly is the orange forum embargo, Sir Humphrey ?
That's to do with the discs. Whose discs are you using? (They sound expensive! Try getting a plain stack of unlabelled ones from PCWorld or similar, far cheaper and with newer drives and burn protection, I haven't wasted any so far. The old TraxData and Kodak discs were AWFUL!) - -- Neil Williams ============= http://www.codehelp.co.uk neil@xxxxxxxxxxxxxx linux@xxxxxxxxxxxxxx neil@xxxxxxxxxxxx -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE+BkxBiAEJSii8s+MRAmYpAKDOXukmKZ49ALqt2uQ6JeGMFO9wEwCcCOeL hpkVtjtJcOfbtdFL7ycbRts= =Mhye -----END PGP SIGNATURE----- -- The Mailing List for the Devon & Cornwall LUG Mail majordomo@xxxxxxxxxxxx with "unsubscribe list" in the message body to unsubscribe.