[Beowulf] Table of best compiler flags for different CPUs?

[Steve Cousins]

On Tue, 10 May 2005, Kozin, I (Igor) wrote:
> It is generally a good idea to look up what other
> published benchmarks used to build their codes.
> Two obvious good sources are SPEC and Stream.
> http://www.polyhedron.com/ is quite useful too.
> But I must admit that the obscure options used
> there were seldom useful to me apart from building
> the respective codes on respective hw.

Thanks.  Someone else suggested spec.org to me offline.  This does have
valuable information but I was hoping that someone had already created a
table like this and it would save time if they might share it.

> >> I am interested in what combinations of compilers and 
> >> switches will give a better comparison, as well as run our 
> >> code faster. 
>
> serial or parallel? Please, post a link if published.

I haven't really posted but here is what I have found:

CPU:         	Speed   CPUs	Time to run:	Compiler and Flags
=============	=======	====	============	====================
PIII 		866 Mhz	  2 	30:10		pgf77 -fast -Mconcur	
Athlon 2800+	2.1 Ghz   1	13:26		pgf77 -fast -Mconcur
SGI MIPS 	400 Mhz	  4	12:08		f77 -apo -O2 
Athlon 3000+	2.1 Ghz   1	11:27		pgf77 -fast -Mconcur
Athlon 2800+	2.1 Ghz   1	10:19		pgf77 -fast -Mconcur
Desktop G5 	2.0 Ghz	  1	9:15		xlf_r  *  
Xeon 		3.0 Ghz   1	9:08		pgf77 -fast -Mconcur
Desktop G5 	2.0 Ghz	  2	7:20		xlf_r  *  
Opteron 	1.6 Ghz	  1	7:15		pgf77 -fast -Mconcur
Xserve G5 	2.0 Ghz	  2	7:11		xlf_r  *  
SGI MIPS 	400 Mhz	  8 	6:55		f77 -apo -O2 
Opteron 	2.2 Ghz	  1	6:10		pgf77 -fast -Mconcur
Opteron		1.6 Ghz	  2	5:37		pgf77 -fast -Mconcur
Opteron 	2.6 Ghz	  1	5:32		pgf77 -fast -Mconcur
Xeon 		3.0 Ghz   1	5:29		pgf77 -fast -Mconcur
Opteron 	2.6 Ghz	  1	3:12		pgf77 -fast -Mconcur

* flags for xlf_r:  -O5 -qstrict -qarch=g5 -qtune=g5 -qsmp -qunroll=yes

The program that was run is a stripped down ocean model (Princeton Ocean
Model) that reads in initial conditions at the beginning and then does a
one day run without any further I/O.

Cheers,

Steve