OT: DAT drives

[Mark Szidik - Michigan Library Consortium]

On 5 Apr 2000, Ben Pfaff wrote:

> Mark Szidik - Michigan Library Consortium <szidikm@mlc.lib.mi.us> writes:
> 
> > I am just a little curious as to why my DAT drive (using dump) writes
> > about 1 MB/s using a DDS1 tape (90Meter) and writes to tape at 4.4MB/s
> > using a DDS3 tape?
> 
> I want to know, too.  Mine only writes 1.2MB/s to DDS-3 tape (and
> 400kB/s to DDS-[12] tape)!  But, seriously, that's normal.  Why
> it happens, I'm don't know.  Here's a wild guess: the speed of
> tape motion past the head is fixed, but bits are stored more
> densely on DDS-3 tape.
> 

This theory works for me.  

BTW: The drive is DDS4 and its on a separate SCSI controller from the
disks.  

For kicks I ran the dump with my one and only DDS4 tape (can you say
expensive) and my average throughput is about the same as the DDS3
tape - 4.1MB/s.  (I would have expected this to be higher given the
density theory)