Easy Way to Happiness

If you’ve ever burned a CD from your home PC, you know how long the process takes ? you copy the files into the working folder, and they get written to the CD-ROM directly. Depending on how fast your CD burner is, and in some cases, the type of files done, this can take upwards of a minute or more to write the disks. Combine that with physically swapping out the media and more and doing a large CD-duplication job can be a serious chore.

One of the main reasons that do-it-yourself CD replication can be so slow is your computer’s bus speed. Bus speed is how fast your computer can relay data to your CD drive. Think of it like this; if you’re writing a 300 MB CD image, it’s fairly quick to load the image into your system. But, once you load it, it must be shoved down a very narrow ‘pipe’ to your CD writing hardware. While bus speeds have come a long way since CD writers become popular, they still slow down the process quite a bit.

Another reason personal CD burning can be slow is data integrity checking. Every time your CD drive writes data to the optical disk, it reads it back to check that it’s correctly written. If any errors are found, it backs up and rewrites the data. This is fine for small home CD-ROM writing applications, but it has some major overhead.

This overhead is a result of file comparison ? it reads and compares the newly written data to the original source file to make sure there are no differences. This occupies a lot of memory, and it sends even more information through that narrow pipe between the motherboard and the CD-ROM drive.

Professional CD replication uses a different procedure entirely. First, when a professional duplicator takes the initial data file, they run the data integrity check when making what’s called a master image. This means that the read-write-verify process is done once per job, rather than once per disk; the first load up takes more time, but burning each copy is faster.

Second, professional equipment has a much faster transmission speed for relaying information to the CD burner. These speeds are comparable to data transmission speeds between various components on your motherboard. The main limiting factor is how quickly the laser that burns the image can move.

Third, a replicator rack can burn about 100 CDs at a time; many of them also feed the disks through a label printer so that the CD-ROM has the label image it’s supposed to have. Each disk image that’s burned this way takes about 25 to 30 seconds per disk, and the entire process is automated, sliding the disk along in assembly line fashion. There are even ‘tappers’ that will automatically sleeve the disks for a job.

Professional CD replication has a number of efficiencies that simply can’t be matched by burning CD copies on a PC. High end equipment and automation make for much faster processing times. Even small professional replicating set ups can burn 20 disks at a time, and are priced within reach of a small business.