Configuration of RS/6000 Model 320

[Mickey Coggins/100000]

In article <2866 at husc6.harvard.edu> khoo at husc8.UUCP (Oonchye Khoo) writes:
>A question for those who already have RS/6000's:
>
>:  8-megs of memory, 320mb hard drives, ethernet cards,
>standard grey scale monitors and a tape drive for one of the machines.
>
>Are the 320's brain damaged in any way?  ie. Should we go with the next model 
>up instead?  

The 320 is not a crippled machine.  It runs nicely. IMHO.
(I *AM* an IBM stockholder ;v)

>Is 8 megs of memory enough, or will the machine run much better with 16 megs?

It will always run better with more memory, until all of the applications
and the kernel running on it fit entirely in RAM.  The main question is
what performance level are you looking for, and how large are the "typical"
applications your users want to run.  Application size is not easy to
compute, but is trivial to figure empirically (just run it and do a 'ps').

Also, the 'lsps' command will show you how much of your paging space is
being used.  AIX V3 is quite clever about memory usage, since almost
all code is shared, so even multiple copies of a large application will
run nicely in a machine with "not enough memory".

>Are 320mb hard drives big enough (we plan to have about 50 users on each
>machine).
>We will be running statistical software with large databases on the machines,
>and will probably run OSF/Motif as well.

This is easy.  The Machine comes with a "planning guide" with some real
paper spreadsheets to calculate how much disk space for the pieces of the
operating system you wish to install.  Subtract the number you come up
with from 304 Megabytes (the real capacity of the 320 Megabyte drive),
then subtract the size of the large databases you plan to use, and
subtract the result of the following calculation:
(#users * amount of disk space needed/allowed per user)

If the answer is less than zero, my stock goes up!
Seriously, you can simply add another 320MB drive, a 120MB drive, or
external 600MB or 800MB drives as needed.

Have fun,
Mickey Coggins  ...!uunet!ibmsupt!mick  512-838-4809 or 512-838-4851 (fax)
                Mail Stop 2831, 11400 Burnet Road, Austin, TX  78758  USA