X-no-archive:yes
Gentle HP 3000 List members,

Ever so mindful of users requests, I present an updated spreadsheet showing
the information about the backup devices HP sells.  I put this in an Excel
spreadsheet which I cut and pasted to this message.  I do not know how well
it will come across.


Device  DDS             DDS-2           DDS-3           DDS-3
                DLT4000                 DLT7000
Medium          DDS-90          DDS2-120        DDS2-120        DDS3-125
                DLTIV                   DLTIV
Capacity        2GB/4GB         4GB/8GB         4GB/8GB         12GB/24GB
                20GB/40GB       35GB/70GB
Xfer Uncm               183KB/s         512KB/s         512KB/s         1MB/s
                                1.5MB/s                 5MB/s
Xfer Comp       366KB/s         1MB/s           1MB/s           2MB/s
                3MB/s                   10MB/s
MTBF            200                     300                     300
300
                                        200                     200

Suffice it to say that DLT is very competitive in media price and has
superior performance over DDS.  These figures are available at the HP Web
site.  I just gleaned them from there and put it all together.

As a backup software vendor, I can say that we experience the figure show
above for throughput and capacity.  I cannot vouch for the MTBF.

If you are looking at the 7000, be aware that in order to get the best
performance out of it, you will have to balance the system, the disc
drives, the controllers and the backup software.  All of these have an
impact on tape performance when you reach those speeds.

Compare the above figure for DDS and DLT to the Redwood drive from
StorageTek at 11MB/s uncompressed.

Kind regards,

Denys. . .

Denys Beauchemin
HICOMP America, Inc.
(800) 323-8863  (281) 288-7438         Fax: (281) 355-6879
denys at hicomp.com                             www.hicomp.com


-----Original Message-----
From:   Neil Harvey [SMTP:[log in to unmask]]
Sent:   Saturday, 22 August, 1998 6:53 AM
To:     [log in to unmask]
Subject:        Re: DDS-3 vs. DLT? Reliability?

After many months of DDS3 (8 drives in total), so far no failures.
This is MUCH better than our experience with DDS2.
So I give the DDS3 a thumbs-up.

Of course, I cant compare it to DLT, because we don't use DLT.

Maybe one of the backup vendors could publish a benchmark..........

Regards

Neil



> -----Original Message-----
> From: Chris Bartram [SMTP:[log in to unmask]]
> Sent: Thursday, August 20, 1998 10:44 PM
> To:   [log in to unmask]
> Subject:      DDS-3 vs. DLT? Reliability?
>
> Howdy,
>
>   Having seen all the past messages about the poor (to be kind)
> reliability
> of "DDS" (and we've replaced a few in our day also), I wonder what the
> current feeling on the latest DDS-3 drives are vs. the DLT-7000s?
>   From HP's specs, the DDS-3 sports a 300,000 mtbf, while the DLT-7000
> only
> sports 200,000 hours...? If *HP's* listing them as *less reliable*,
> should
> that tell us something?
>
>   With DLT-7000s listing for (what was it?) $13k* each(?), with 2-3
> times
> the capacity of DDS-3, and twice(? my memory fails and I don't have it
> in
> front of me at the moment) the throughput... I'm wondering if the jump
> to
> DLTs are really worth it?
>
>   Any opinions? Are *all* DDS drives just evil?
>
> *=HP List price
>
>          -Chris Bartram
>
> P.S. For any HP folks reading; the DDS2 spec sheets on the hp.com web
> site
>     have a nasty typo in throughput; I believe the "compressed"
> numbers are
>     in Mb, not Kb as listed. :-)