RS/6000 Multiuser Performance

[Jason Heirtzler]

In article <27718 at uflorida.cis.ufl.EDU>, brs at cis.ufl.edu (Ray Seyfarth) writes:
|> I am curious about experiences of users of RS/6000 model 320 systems
|> with multiple users.  In particular I would like some feedback from
|> users with about 30 X terminals attached to a 320.  What kind of
|> performance is achieved..

Has anyone else noticed problems with the ethernet controller on the
model 320?   Some testing I've done seems to indicate that TCP
throughput is limited to about 400KB/sec, which is quite slow.  Even
stranger is that if I reduce the size of the individual packets (say
if the size of the packet changes from 1500 bytes down to 64 bytes) I
still can't send much more packets/sec than with the larger packet
size.  The throughput would naturally decrease with smaller packets,
as you would expect, but you should to be able to send more packets/sec
if they're smaller.  It's really odd!

It is possible that our controller is still a pre-GA version, and
we are getting it swapped to a newer one (part 718 1182) to see if
this helps.

|> I am interested in using X terminals in an academic setting.  There
|> would be a lot of editing and a moderate amount of other activity.
|> 

Last week I posted a similar question, but noone responded with more
than 65 simultaneous users (not xterminal users, but "generic timesharing"
users, if there is such a thing) so let me ask again: Does anyone have
an RS-6000 with more than 50 simultaneous users?  If you do, your input
would be greatly appreciated!

jdh

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Jason Heirtzler           (617) 353-2780       jdh at bu-pub.bu.edu
Information Technology    Boston University    ..!bu.edu!bu-pub!jdh