Kindly have a look at
http://jazz.external.hp.com/papers/TSWhitePaper.html

Regards,
Bijo

"Bill Green" <[log in to unmask]> wrote in message
news:v5b482phvga008@corp.supernews.com...
> There is a problem with high performance DLT operation, software
compression
> and system performance.
>
>
>
> When replacing a DDS3 with a DLT7000 FWD tape drive we should see a
> performance increase of at least 4 times the performance.  If everything
is
> configured for performance you should get roughly 7.2Gb of storage with
> compression on a DDS3 drive and roughly 35Gb with hardware compression.
> When software compression is thrown in the equation there are different
> results depending on the performance of the system.  The reason seems to
be
> due to the CPU having to compress the data and pass it on to the DLT
Drive.
> The DLT is a streaming device and would prefer the data to continue
without
> stopping.  Simply the DLT is having to stop and sometimes reverse to start
> again.  Using my technical term "wish/wash".  I have used the maxtapebuf
32K
> option with little to no help as the DLT7000 is backing up much faster
than
> a lousy 16KB increase.
>
>
>
> I have seen this occur on a number of smaller systems.  Once you get into
a
> multiple processor system of any kind or really anything faster than
987/988
> the problem goes away.  Of course the other way is stop using the software
> compression software.
>
>
>
> Does anyone have any ideas in this regard..
>
>
>
> Regards,
>
>
>
> Bill Green
>
>

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