Re: Why is the iSeries so slow

[Mike.Crump@xxxxxxxxxxxxxxxx]

I actually hate to jump in here but one thing we all have to remember is
that sometimes our evidence is incidental in nature.  I have no doubt that
the problems that a lot of you have mentioned are indeed valid cases.
However, everything is relative - we use our iSeries for a great amount of
consolidated functions - Domino, Quickplace, Websphere, HTTP, file serving
(granted not a lot), FTP processing (encrypted and not), green screen, end
user queries, etc.  and have not run into any of the problems that have
been mentioned.  So, in my world I don't have this problem.  And one of the
main points that Joe was making was that a lot of the points were valid but
were possibly out of context.

Now, in my case take that application list.  When my machine was a 720 it
was not overloaded.  However, Domino performance was average and 20% of my
Websphere transactions were awful.   Moving forward to an 820 and then
eventually the 825 those problems disappeared.  Yes, I increased CPW but in
this circumstance most of us know that Mhz and L2 cache were probably the
significant contributors.

Buck, I don't agree 100% with the task to task comparison.  I understand
your point.  In our world we've done some testing (not comprehensive mind
you).  We use the system for web serving - it is approximatly 15% slower
than serving done on a decent sized PC server.  Of course we know that
everyone's mileage will differ - in our case we said '15%?  No one will
notice.  For us this was pretty consistent.  For file serving we saw 10-20%
and that had a lot more volatility.  20% sounds like a lot but effectively
to the end user?  In almost all cases insignificant.  I'm not trying to
dismiss the needs of the end user but if I look at my page serving and
compare a 3 second response to 3.3 seconds?  For these functions we saw the
slightly degraded performance as a nit when we looked at the cost savings
and simplification in our environment.  We can argue cost of ownership
until we are blue in the face but it is relatively consistent that less
servers means less costs.  It's true when I've reduced our
AS/400's......and even the Microsoft marketing machine with it's Windows
2003 and Active Directory commercials is emphasizing the same thing.

Now, if those applications truly performed significantly worse...it
wouldn't be worth the hassle.  In our case the mantra does work - it could
for many others but it's not a guarantee.  Now, that I've added potential
fuel to the fire I think I will go back to read mode.....






                                                                                
                                                       
                      Buck                                                      
                                                       
                      <buck.calabro@xxx        To:       
midrange-l@xxxxxxxxxxxx                                                       
                      msoft.net>               cc:                              
                                                       
                                               bcc:                             
                                                       
                      08/13/2003 02:07         Subject:  Re: Why is the iSeries 
so slow                                                
                      PM                                                        
                                                       
                      Please respond to                                         
                                                       
                      Midrange Systems                                          
                                                       
                      Technical                                                 
                                                       
                      Discussion                                                
                                                       
                                                                                
                                                       



> You're comparing a multi-user multi-purpose server
> box to a dedicated controller.  The iSeries IS NOT
> MEANT TO BE A DEDICATED PROCESSOR.

I think that we are all in complete agreement on that point.

What we are saying is that the IBM mantra of 'server consolidation' flies
in
the face of economic reality.  With an 820, we are told that we can run
MANY
DIFFERENT workloads on that machine, including a web server (1).  We tried
that, and found worse performance than with the PC.  And the PC has very
similar uptime to the 820.

The problem is that when the PC network guys say "Hey!  We can host that
website on our existing PC network and it'll be faster than your
mainframe."
They are comparing one task (web serving) between their platform and ours.
And ours loses for THAT task.  When we compare OLTP processing to their PC
network, we kill them.  Task for task is the comparison, and that's what
makes it a valid one, I think.

I just think that if IBM is serious about this 'e-server' business they
should make their e-business functions kick serious butt, rather than be
approximately adequate.
--buck