From: Ciaran McCabe (cmac at domain clubi.ie)
Date: Mon 31 May 1999 - 16:47:45 IST
Just a few thoughts,
The sustained transfer rate can be achieved (at least with the 2940's I tested,
though not linux attached) but the data rate on SCSI bus will be higher than the
calculated value due to the characteristics of the medium and assuming 100%
connection integrity. The use of dual channels would, of course, help the
scenario.
The better of the stand-alone copiers as mentioned in another posting could
provide a more reliable solution because the system should be tuned for optimum
connection integrity.
However, it should also be remembered that the requirement is for audio copying
and there are a number of issues that this may raise. Reliable copying will have
to be fully tested and the quality of the "reader" will be of paramount
importance. Simply "ripping" the data off the master and burning multiple copies
may not always yield the desired result. Of particular importance may be the
requirement for Blue-Book CD's (the true technical specification for the loose
grouping of enhanced CD's) which is becoming more prevalent for audio work in
general and demo/promo discs in particular. Also the output of the chosen
solution will have to be tested to ensure that it is mass replication ready, if
that is a possibility.
Regards,
Ciaran McCabe
Open Systems Consultant
Niall O Broin wrote:
> Vincent said
>
> > Even assuming 4x CD Writers, that's still only 7x600k = 4.2MB/s
> > throughput on the SCSI bus, with minimal CPU overhead and very little
> > disk reading, because it'll cache everything after the first read.
>
> This sounds sweet and wonderful, but you're assuming that you can maintain
> a sustained throughput for ~15 minutes which is 42% of the theoretical
> max. throughput (I don't know if there are any Ultra or UW SCSI burners).
>
> I'd be dubious, though I imagine with a fast machine and two SCSI channels
> to spread the load, it might be doable. But you're only going to know it'll
> fly if you suck it and see, or find someone who has done so already.
>
> Kindest regards,
>
> Niall O Broin
>
> UNIX Network Administrator nobroin at domain esoc.esa.de
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