From: wolpers@i11s10.ira.uka.de (Andreas Wolpers)
Newsgroups: comp.arch,comp.benchmarks
Subject: Re: Lisp performance (on Sparc SS2, SS10-30, HP720)
Date: 16 Nov 1992 14:28:28 GMT
Organization: University of Karlsruhe, FRG
Distribution: world
NNTP-Posting-Host: i11s10.ira.uka.de

In article <Bxt992.BJB@pix.com>, stripes@pix.com (Josh Osborne) writes:
|> In article <1e824rINNlpu@iraul1.ira.uka.de> wolpers@i11s10.ira.uka.de (Andreas Wolpers) writes:
|> >Hello everybody,
|> >
|> >I'm having a minor problem on which I would welcome any comments:
|> >Since I'll have some money to spend real soon now, I've been pondering
|> >whether we should switch from Sun to HP. The usual benchmark results
|> >suggest that a change might result in faster execution of our pet
|> >program, a large "theorem prover" written in Lisp.
|> 
|> You should get Sun and HP to send you computers to test, then send back
|> the slowest.  From your comments below, I assume that you at least got
|> Sun to send you a machine...

I have a bunch of SS2's, and Sun recently brought us a SS10-30 for testing.
HPs are found in our computer center. The (only) problem with you suggestion
is that the money must be spent before Dec. 6, and the machines which I
intend to buy are not yet available :-(

|> >From the SpecInt92 results, one should expect a performance increase
|> >of about a factor of 2 when switching from a SS2 to either s SS10-30
|> >or HP720. Unfortunately, on both machines turned out to but just
|> >30% faster than a SS2 when running our system (for which ps NEVER
|> >shows a resident set under 3-4 MB, not even on an 8MB machine).
|> 
|> (a) I am sure the SPECInt's ops were all normal add's and sub's, and
|> I am guessing that Lisp's are all taged add's and sub's.  Can you
|> execute >1 tagged op per cycle?  Also did you re-compile the lisp
|> interpreter on the SS10 with a compiler that can schedule code for
|> the new CPU?

For lack of a new Lisp compiler, this was impossible. We DID recompile
some of my collegues floating-point benchmarks. They became slower.


|> (b) If you only have 8M, you may be out of RAM even when ps says your
|> code is only using 3-4M.  First, ps doesn't (by default) report pages
|> [...stuff deleted...]

All the machines used for testing had 32 MB minimum, and not much else
running (an "idle" X or openwin, and our test takes 8-12 minutes to
execute). I referred to the 8MB machine just to show that one can't do
with a smaller amount of memory.

|> 
|> [stuff deleted]
|> 
|> How long can you wait?  Wait long enough and lisp machines will come
|> back into style (half :-) ).
|> 

About 11 days. while true do :-( od

|> >Should I give YOU the money? :-)
|> 
|> Yes, in small unmarked bills.

Sorry, just cheques, no cash.

|> -- 
|>            stripes@pix.com              "Security for Unix is like
|>       Josh_Osborne@Real_World,The          Multitasking for MS-DOS"
|>       "The dyslexic porgramer"                  - Kevin Lockwood
|> We all agree on the necessity of compromise.  We just can't agree on
|> when it's necessary to compromise.       - Larry Wall

-- 
Andreas Wolpers
e-mail: wolpers@ira.uka.de
phone:  49-721-608-3977
fax:    49-721-697760