~Factors In CD Duplication


The process of writing data to a recordable CD can

be a complex process, as it demands a lot from both

hardware and software programs.  Much of this 

complexity is hidden from the user by the program,

although you should be aware of these factors.


The total amount of data you are writing is much

less important than whether or not it contains large

or several small files.  If there are a lot of 

small files, the system may have problems with

locating and opening the files quickly enough to

send them smoothly to the CD recording drive.

The computer

Any interruption that may occur is fatal to CD

duplication, so you should ensure that your 

CONFIG.SYS and AUTOEXEC.BAT don't load any TSR

utilities which may interrupt operations.  Screen

savers, alarms and reminders, or incoming faxes 

may also kill disc writing.  You should also turn

off network sharing so no one will access the files

that you are trying to write, as this could also

kill your disc recording.

Hard Disk Speed

To write an image to the CD, the hard disk from

which you are writing must have a transfer rate 

that is fast enough to keep the memory buffer full

in the CD recorder.  This normally means an average

hard disk access time of 19 MS or better.


If your hard drive has to search everywhere over

a fragmented hard drive for the data to be written,

it can cause the operation to slow down or even

cause a fatal error.  Therefore, always be sure to

fragment your hard disk drive.

Recording speed

Most new CD recorders and even some older ones,

are capable of writing at two (sometimes even four)

times the standard playback.  It should be possible

for you to select the speed; as even though fast

recording is a time saver, it can also cause some

bad situations.

When you copy an ISO (image file) from the hard

disk to a CD, the speed is rarely a problem as the

image is already one large file in which the 

files and structures are already in order and 

divided into CD-ROM sectors.  

When you write from a virtual image, things can

get a bit trickier.  In order to copy to CD, the 

program must consult with the database to find

where each file should go in the image and where

it is actually stored on the hard disk drive.

Then, it must open the file, divide it into CD-ROM

sectors, at the same time sending the data in a 

smooth continuous stream to the recorder.  Locating

and opening the file is a bit more time consuming,

as writing is more difficult if you have a lot 

of small files.

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