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From: klimas@iccgcc.decnet.ab.com
Newsgroups: comp.object
Subject: Re: Performance of Smalltalk vs C (or C++)
Message-ID: <2995.27a59704@iccgcc.decnet.ab.com>
Date: 29 Jan 91 20:38:44 GMT
References: <1991Jan4.004138.7013@ashtate> <22574@well.sf.ca.us> <2961.279ffcba@iccgcc.decnet.ab.com> <3282@sequent.cs.qmw.ac.uk>
Lines: 25

In article <3282@sequent.cs.qmw.ac.uk>, eliot@cs.qmw.ac.uk (Eliot Miranda) writes:
> In article <2961.279ffcba@iccgcc.decnet.ab.com> klimas@iccgcc.decnet.ab.com writes:
>>In article <22574@well.sf.ca.us>, jjacobs@well.sf.ca.us (Jeffrey Jacobs) writes:
>>> Performance is generally on the slow side.  This really isn't a compiler
>>
>>	If performance in modern Smalltalk's is a problem then it
>>	will be a problem in C also.  We have seen Smalltalk programs
>>	actually run faster than the C programs they were replacing.
> 
> Can you post more details?
> 	kind of program
> 	simple metrics (k lines, k bytes of code)
> 	% speed increase?
> 
> I also remember vaguely hearing from ParcPlace about Smalltalk to C++
> rewrites that didn't produce the expected speedups. Can anyone comment
> on this too?

	One tidbit I can share with you, was a case history that was reviewed
	at the Workshop on Real Time OOP at OOPSLA90 in Ottawa.  One of the
	participants from a French firm told of an attempt to rewrite a large
	military discrete event simulation from Smalltalk-80 to C++.  When all
	was said and done, the C++ incarnation ran only 10% faster (i.e. the
	more object oriented your program the more its performance will be
	like Smalltalk).