On Wed, May 21, 2003 at 07:43:16AM -0400, Andrew Heybey wrote:
> > Greetings.  I have a Sony SDX-500C AIT-2 tape drive (50 GB native).  I
> > have been using the following entry for my tapetype, obtained from
> > various places in the mailing list (I have no idea how this was
> > originally generated):
> > 
> > 3) Neither 54538 mbytes nor 48898 mbytes corresponds to 50 GB, no
> >    matter how I do the math (i.e. no product of 50, 1000s and 1024s
> >    generates either of these numbers, and 54538/50 = 1090.76 MB/GB,
> >    48898/50 = 977.96 MB/GB).  I'm (obviously..?) more inclined to
> >    believe the smaller number, given the ways of marketing, but does
> >    anyone have a quick explanation of how tapetype calculates this
> >    number..?
> 
> As to the discrepancy between tapetype's number (48898) and the
> advertised size of the tape, I do not think that there is much of a
> discrepancy.  Actually, tapetype is coming up with a slightly larger
> number than advertised.  Don't forget that amanda does everything in
> power-of-two kb (1024) & mb (1048576) while disk and tape
> manufacturers advertise in power-of-ten numbers.
> 
> 48898 * 1048576 = 51273269248, which is 1273269248 bytes larger than
> the advertised 50000000000 bytes.  Don't worry, be happy!


Gee,
        (48.898*1024*1024*1024 - 50*10^9) / 50*10^9 * 100

is only an excess of 5 percent.  Sony is gyping you,
I thought they were supposed to give an excess of 40%!!   :))

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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