CD copy speeds

vbimport

#1

I have done a couple of searches, but can’t find an answer (maybe I’m using the wrong search criteria) even though I know I’ve read it here before.

What is the genreal rule of thumb for producing reliable copies (of Karaoke CD+G discs)? I seem to remember that either reading or writing should be twice the speed of the other, but can’t remember which.

I’m using Alohol 120 with a Plextor 48/24/48, and I get very good results at 4x (for both) and mostly good results at 8x, but would like to get them a bit faster if I can.

No biggie if I can’t. Quality in this case is far more important than speed.

TIA,
Tim W.


#2

Originally posted by GoAheadMkMyDay
What is the genreal rule of thumb for producing reliable copies (of Karaoke CD+G discs)? I seem to remember that either reading or writing should be twice the speed of the other, but can’t remember which.

You can’t write at more speed than you’re reading… it’s obvious :cool:
If the drive is reading at 12x, that’s the maximum writing speed… well, you can select faster speeds, but the writer will have to stop a lot of times until more data is available from the reader.

That was said in the old times when burners didn’t have BurnProof protections and burns failed when there were buffer underruns (data was not a available at enough speed).
Double the speed was said in order to give you an idea. It’s obvious that it’s enough with equal speeds, but in this case any slight interuption in the data flow and there will be a buffer underrun.

[B]

I’m using Alohol 120 with a Plextor 48/24/48, and I get very good results at 4x (for both) and mostly good results at 8x, but would like to get them a bit faster if I can.
[/B]

You only have to see at what speeds that disc can be read.
Use CDSpeed for that.

That’s why a lot of people reads to an image before burning.
You can’t know what is the reading speed of a disc until you read it. Small errors may stop/repeat or slow down the reading speed.


#3

I guess I should have made it clearer. I am using the Plextor for both reading AND writing, with the temporary file stored on the HD. Given that reading and writing are now separate processes, is the “rule” still applicable? Can I burn at ANY speed from the image files? It has been said, that it is more reliable to copy at low speeds, and I know that the real answer is that the only way to find out what will work on my configuration is to try it, but I’ve just made so many coasters so far, I’d like to take advantage of some of the experience out there.

Background:
I have an external Lite-on 24x USB CD-RW, and, try as I might, using every option in every program I could find, I was not able to backup a single CD+G disc. So I broke down and bought the Plextor, which seems to work very well. I’ve just added a 160MB HD to my system, and I think I want to keep the backups, so I can burn them again when - sorry, I mean IF … my wife keeps losing the discs.

TIA,
Tim W


#4

Originally posted by GoAheadMkMyDay
is the “rule” still applicable?

No.
It even wasn’t necessarily applicable in the old days…
Data can be read at whatever speed because it can’t be read with errors. Of course, disable any box that says something like “Ignore reading errors”. Errors shouldn’t be ignored (unless copying a protected disc).

[B]

Can I burn at ANY speed from the image files?[/B]

No. Well, yes but there are several issues.
1st, your hard disk should read fast enough to mantain the data transfer. This isn’t usually a problem.
2nd, the data is digital but media is not. The “shape” of pits and lands may be slightly different depending on media, writer, compatibility between both and writing speeds. This can make the discs more difficult to read, usually very high speeds and not very good media have too many low level errors, but it can happen at other speeds too.
Your drive isn’t really very fast, so you should be able to write at 16x or 24x with good quality.

http://www-user.tu-chemnitz.de/~noe/LiteOn/C1-scans/

[B]

but I’ve just made so many coasters so far, I’d like to take advantage of some of the experience out there.[/B]

Your drive has some kind of buffer underrun protection, so it’s not a matter of buffer underruns (too high speed).
Maybe media is not good enough and fails (I don’t think so).
Probably, it’s USB at fault. USB is a not reliable bus. Most people here use IDE or SCSI bus.


#5

minix has somewhat summed it all up, thanks for taking the time to reply :slight_smile:

GoAheadMkMyDay, there should be no problem with either you reading or writing speed. Even if your hdd is not able to provide the data to your drive while writing (which is unlikely if you’re burning @ 24) this should not result in a coaster. If you provide us with more details about the error messages you get we might be able to help a bit more.


#6

Thanks for all the advice. I’m going to try some experiments tonight with different reading and writing speeds. I’ll report the results later in the week.

Tim W.


#7

Of course, I suppose you have USB 2.0.
USB 1.x can’t burn faster than 4x.

I think that Alcohol shows the state of the buffer (I don’t remember), so you can that the burning speed is too fast if buffer underruns happen.

You don’t have to experiment with reading speeds. It doesn’t matter the reading speed as long as there’s no error, and data discs can’t be read with errors (there will be a warning).

For audio ripping, you can use software that shows C2 errors like PlexTools, Feurio or EAC.


#8

OK. I broke down. My curiosity is greater than the 15c it costs for a bunch of test discs, and my time isn’t of any value, 'cos I don’t got a life!

For those that are interested, I am about half way through my tests, and the results so far are listed below.

Goal:
Work out the best method for copying CD+G discs on MY system.

Constraints:
Quality over speed
Using Alcohol 120%
Only on MY configuration

Test Strategy
Impact of reader type
Impact of read speed
Impact of writer type
Impact of write speed

Test Plans
Read a known problem (plays OK, but copy fails with LO drive) CD with a each reader and at a variety of speeds to an intermediate file (i.e. NO copying on the fly)
Write CDs from ALL intermediate files using both recorders
Play CDs in Karaoke CD player

Results

Reader (Speed)…Observed Speed…Recorder (Speed)…Observed Speed…Result
N/A…N/A…N/A…N/A…Test CD. Audio good. All songs readable.
LO (4x)…4x…LO (4x)…4x…Audio good. Karaoke very bad. All songs mostly unreadable. (These results from initial attempts several months ago)
LO (Max)…20’s-30’s x…LO (Max)…22x…Audio good. Karaoke bad. Most songs unreadable. A few songs OK.
PLX (Max)…8x-16x…LO (Max)…22x…Audio good. Karaoke OK. A few very minor glitches only.

Legend:
LO = Lite-On 24102B (Ext. USB2.0)
PLX = Plextor 4824A (Int. ATAPI)

Notes:

  • The intermediate file size on each dump was identical. I’m OK. I broke down. My curiosity is greater than the 15c it costs for a bunch of test discs, and my time isn’t of any value, 'cos I don’t got a life!
  • I don’t understand why the PLX read the discs so much slower than its max. speed and the “slower” LO drive. Must be reading other info that the LO can’t access, I guess. There are NO errors shown during either reading or writing.
    looking for a decent file compare utility to examine the contents in detail, as there must be differences (the burnt CDs don’t work the same).
  • I don’t understand why the PLX read the discs so much slowere than its max. speed and the “slower” LO drive. Must be reading other info that the LO can’t access, I guess.

#9

Originally posted by GoAheadMkMyDay
- I don’t understand why the PLX read the discs so much slowere than its max. speed and the “slower” LO drive. Must be reading other info that the LO can’t access, I guess.

well, I know there are Plextor drives that read audio slower if index marks (subchannels) are read at the same time… speeds may be slower in raw modes (I never use raw modes, so I don’t know how they work).

Plextor drives are known to burn CD+G discs correctly. Did you use the Plextor to burn them?
Have you tried PlexTools?

Why don’t you try programs that specially support CD+G: CDRWin, DiscJuggler, DART Karaoke Studio CD+G.
http://www.dartpro.com/support/devices.asp#CDGRecorders


#10

Originally posted by minix
[B]Plextor drives are known to burn CD+G discs correctly. Did you use the Plextor to burn them?
Have you tried PlexTools?

Why don’t you try programs that specially support CD+G: CDRWin, DiscJuggler, DART Karaoke Studio CD+G.
http://www.dartpro.com/support/devices.asp#CDGRecorders [/B]

Before I bought the Plextor drive, I tried backing-up the discs with the Lite-On using Nero, CloneCD, Alcohol, and DiscJuggler, all of which claimed to be able to do it, and I haven’t had a single success. With the Plextor as the reader, using Alcohol 120%, I have been able to burn the image to CD using either the Lite-on or the Plextor. Now I’m just trying to optimze the process.

My initial conclusions from my tests seem to confirm that read speed may not be a factor when not copying on the fly, and that once a good image is created, any drive capable of RAW writing can burn the image to CD at any speed.

Once I’ve got everything backed-up, I would like to get one of the other programs that allow me to create my own CD+G compilations, for which a fully CD+G compatible CD-R will be necessary (another reason I bought the Plextor).

Tim W.