RE: 890 cpw per cpu

["Steve Richter" <srichter@xxxxxxxxxxxxx>]

-----Original Message-----
From: midrange-l-admin@midrange.com [mailto:midrange-l-admin@midrange.com]On
Behalf Of John Myers - MM

>There is a certain amount of overhead consumed in managing multiprocessor
>systems ... the total CPW rating reflects that overhead.  Doing the
>division by 32 gives a per processor total that assumes the overhead and
>that each processor is being used at 100% of capacity.



( from the iSeries handbook, v5r1 )
model 840, #2354.  Cpw 15150 to 20200. Processors 18 to 24.  Processor
speed: 600 Mhz.

15150 / 18 = 841 CPW per processor.
20200 / 24 = 841 CPW per processor.

Model 890. 37,400 CPW. 32 Processors.  Speed: 1.2 Ghz ( as per press
reports )

37,400 / 32 = 1168.75 CPW per processor.

1168 CPW = 140% of 841 CPW.


Hi John,

What you say re: cpw per processor will decrease as the processor count is
increased makes sense, but the numbers for the 840 are to the contrary. CPW
per processor stays the same as processor count goes from 18 to 24. This
pattern holds for other models also.

CPW per processor has increased by 40%.  I understand that processors are
different, cycle numbers don't indicate actual performance, etc, etc, ...
I am just asking if the new 1.2Ghz Power4 is only 40% faster then the 2 year
old 600 Mhz ISTAR.

The 800 - 1000 cpw per processor iSeries models were introduced in May 2000.
2 years later IBM announces a 40% improvement in one model and then states
that there will be no more hardware announcements for the rest of the year.
Effectively, no improvement in CPW for 3 years.

I think our system needs more CPW across the board on the iSeries. How many
useful features are left out of os400 because the cpw of the low end models
would not handle it ?  Like built in journaling and commitment control on
all physical files. Real save while active. LOGCLPGM(*Yes) as the default on
all jobs.

I am working with remote pgm calls and remote command right now.  On a 420
cpw 720,  remote DSL connection,  I can run about 4 "sndmsg" commands per
second.  Performance like that is more then acceptable for some
applications.   But what if a VB application wants to RPC for every control
on the form.  Filling a ListBox with 20 entries alone could take a few
seconds.

( yes, this benchmark is remote.  But based on ADO performance when local, I
estimate local performance of 10 "sndmsg" cmds per second. )

I am designing activex and vb classes that will make access to the iSeries
database and user program resources a single VB statement away.  Why does
IBM limit this capability by not providing the CPW needed to do the job?

Steve Richter
AutoCoder, LLC