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Conference nicctr::kap-users

Title:	Kuck Associates Preprocessor Users
Notice:	KAP V2.1 (f90,f77,C) SSB-kits - see note 2
Moderator:	HPCGRP::DEGREGORY

Created:	Fri Nov 22 1991
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	390
Total number of notes:	1440

373.0. "Benchmark two times slower with KAP Parallelization" by TBC001::WONG () Mon Mar 24 1997 21:28

I'm having serrious difficulties with Parallelization on a customer benchmark.
The Fortran program supplied by the customer runs twice as slow using KF77 with
-conc and two processors.  It's even worse with KF90 (three times slower).  
Unless we can come up with better results soon, the sales opportunity is in jeopardy.

I'm using the latest SSB versions of compilers on UNIX 3.2G.  The customer code
is too big to be shown here.  It will be most appreciated if someone can telnet to
my machine and take a look.

Telnet Instructions:

	>telnet 16.155.48.56   (or set host to TBC001 via DECnet)
	username: guest2
	password: guest210
	$set host/dte txa10   (if txa10 is not available, try txa11 and up to txa15)
	local> conn a8400a
	login: wong
	password: jw

Program Instructions:
	a8400a> pe    		(this will cd to the program directory 'em')
	a8400a> make -f pmakefile	(makes parallel version. The single processor
					version that runs faster is created with
					the make file 'makefile')
	a8400a> cd ps
	a8400a> nohup time pspml.x < ifdem &

T.R	Title	User	Personal Name	Date	Lines
373.1	More Info on .0	TBC001::WONG		`Mon Mar 24 1997 21:42`	29
	More information on .0: The single processor run completed on a AS4100 466MHz system in 414.4 sec. The parallel version with PARALLEL=2 completed in 849.4 sec. The same program ran with different input file (ifdem in 'em/fd' instead of ifdem in 'ps/fd') parallelized well. Single processor run was 600 sec whereas dual processor run was 314.5 sec. Compiler versions were: DFABASE410 installed Digital Fortran 77 V4.1 for Digital UNIX Alpha Systems DFACOM410 installed Digital Fortran V4.1 Tools & their Man Pages DFADOC410 installed Digital Fortran 77 V4.1 Release Notes and Man Page DFARTL373 Digital Fortran RTL #373 for Digital UNIX Alpha (f77 only) DFARTL374 installed Digital Fortran RTL #374 for Digital UNIX Alpha (f90 and f77) F9ABASE410 installed Digital Fortran 90 V4.1 for Digital UNIX Systems F9ADOC410 installed Digital Fortran 90 V4.1 for Digital UNIX Release Notes and Man Page KF9BASE310 installed KAP Fortran 90 for Digital Unix Optimizer KPFBASE310 installed KAP for DEC Fortran for Digital Unix Optimizer
373.2	observations	MSBCS::SCHNEIDER	Say it with ASCII	`Tue Mar 25 1997 12:48`	14
	I will offer a couple of observations, for what they're worth. - I personally find working on TBC systems via that DTE path to be unwieldy to the point of impossibility. You might want to package up the materials and provide a pointer so that any volunteers can work locally. I see there are only a couple of MB worth of files there. - I see source file names that indicate that FFTs are involved. If the FFTs are the bottleneck, it's likely that the right thing to to is use DXML. Parallel FFTs are available in DXML. Cheers, Chuck Schneider
373.3	Response to .2	TBC001::WONG		`Tue Mar 25 1997 14:33`	11
	ref .2 I must apologize for the slowness of the connection. However, I cannot provide a copy of the code on the network because the customer is super-sensitive about it. We tried using DXML before. It didn't improve performance and it created different results. Seems like the customer's routines are non-standard. Thanks for your comments anyway.
373.4	password in notesfile is a no-no	PERFOM::HENNING		`Wed Mar 26 1997 17:47`	8
	> I cannot > provide a copy of the code on the network because the customer is > super-sensitive about it. Then for goodness sakes what be ye doing POSTING PASSWORDS in an unrestricted notesfile??????????????????????????????????????????
373.5	Response to .4	TBC001::WONG		`Thu Mar 27 1997 23:45`	18
	ref .4 Mr. Hanning, Seems like you are even more sensitive than my customer! You must have had some very bad experiences. Thanks for your concern anyway. The customer files are on another system which can only be reached via reverse lat. That makes it difficult (not impossible) to copy them. It's a compromise. Anyway, the account just expired today. Don't lose sleep over it! Joe
373.6	apology for too many ????	PERFOM::HENNING		`Fri Mar 28 1997 19:45`	3
	sorry, I didn't mean to get so excited. /john