RE: How are CPU Speed and Overall CPW Related? -- MIDRANGE-L

I was going to stop posting to this thread, Chris.  But, I'll answer your
questions.  I ran the job interactively with the maximum time slice possible
(99999 *MS I think).  The job used the base memory pool - which held about
270 MB of Ram.  I also ran the job while the system was in a restricted
state (ENDHOSTSVR *ALL, ENDTCP, ENDSBS *ALL).  The 200 Mhz system is a
single user development machine.  I think both systems were at OS V4R4.  But
it didn't make any material difference.  The 100 Mhz machine was still much
faster.

If you follow this thread from the beginning - IBM's Alexei Pytel has been
doing his darnedest to explain the difference.  Wasn't it clear?  Maybe he
could take one more shot at it?

Nathan.

> From: Chris Bipes <chris.bipes@cross-check.com>

> Get the time slice and run priorities of each job on each machine.  Also
> check the memory pool the job is running in on each machine and see if
there
> is any non-data paging.  Also check for the levels of the OS.  4.5 runs
> faster than 4.4 which is faster than 4.3 ....  Also, did Ken fully
optimize
> his program and you did not?  These are all factors that effect
performance.

> - -----Original Message-----
> From: Nathan M. Andelin [mailto:nathanma@haaga.com]
> Sent: Tuesday, May 01, 2001 11:53 AM
> To: MIDRANGE-L@midrange.com
> Subject: Re: How are CPU Speed and Overall CPW Related?

> It's great to get a response from you, Alexei.  I think we all appreciate
> your insider insight.  I won't bother adding more memory now, because at
> this point I'm interested in raw CPU speed.
>
> I'm aware that CPW is a measure pertaining to a mixed workload under load
> testing and is affected by overall system design, but I still question
> AS/400 CPU performance.
>
> I wondered about a CPU governor for several reasons.  The program we were
> benchmarking was entirely CPU bound.  The program simply repeated a few
> String functions, in memory, maybe 100,000 times within an RPG do while
> loop.  Both machines had about the same RAM.  Neither had L2 Cache.  I'm
> talking about a model 170-2160 and a model 170-2290.  Yet the 100 Mhz
> machine executed the code faster than the 200 Mhz machine.  If I were
> running the same logic on a pair of Intel boxes, identical in every way
> except Mhz, then I'm fairly certain the higher Mhz machine would be
faster.
>
> What makes the AS/400 CPU different, in this limited scenario?
>
> Thanks,
>
> Nathan.


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