Many, many years ago, before I even started working on HP3000s,
I worked on HP1000s (it even had IMAGE.)

The local salesman had Meier's law: Add more memory!
Now this was in the days where a 2mb HP3000 was a nice box,
and you added a 4k byte memory card to your 2640b terminals
to allow display of an entire page of text!

I think this is still a good law.  If you have any
system that has been running on 256mb, or 512mb or so,
adding another gigabyte of memory can't hurt
and most likely will help some or most of your applications.

When I checked last week, third party memory for the 9x9
series was $3300 for a 512mb module (and around the same
price for 256mb of official HP memory.)
Now you can spend thousands of dollars to
determine your performance bottleneck, or just go ahead and
add some memory and see what happens.

One thing I have seen happen is that the data bases gradually grow
to the point that they overflow main memory. What was a good
size at one time in no longer enough later on. If you have
been adding disc space to support larger data bases,
you should also consider adding main memory as well.

Once you get most of your working set of data in
main memory, physical disc I/O can drop to almost
nothing and you become limited mostly by the cpu speed.
Of course, if you are busy calculating prime
numbers or compressing files, cpu will be the limiting factor,
but for many commerical applications that
update data bases, random disc I/O is still a
main limiting factor.


-----Original Message-----
From: Dennis Heidner [mailto:[log in to unmask]]
Sent: Thursday, August 03, 2000 4:40 PM
To: [log in to unmask]
Subject: Re: [HP3000-L] AutoRAID 12H performance ?


You did not mention how much memory you have in your 939KS.  You may be
able to "earn" back (plus more) and loss in speed that an AutoRAID 12H
introduces by adding additional memory to the HP e3000.

The data locality for your application makes a significant difference on
the speeds you will be seeing from the AutoRAID box.  Data locality is
dependent on the size of the database, the organization of the database
(linkages), how often you clean up and optimize (repack) the database.