Archives


- Beowulf
- Beowulf Announce
- Scyld-users
- Beowulf on Debian

fortran compiler

Many of your questions may have already been answered in earlier discussions or in the FAQ. The search results page will indicate current discussions as well as past list serves, articles, and papers.

Search

John Casu casuj at valinux.com
Fri Oct 27 20:11:13 PDT 2000


> On Fri, 27 Oct 2000, Robert G. Brown wrote:
> > 

..snip..

> The same should work with Absoft.
> It would be a shame to build the Fortran interface with g77:
> You gain a factor of 4 or more in speed with ATLAS and you loose a factor
> 2-4 with g77 ...
> 

I stand corrected wrt the c compilers:

For PGCC (Portland compiler) I get the following extracted numbers from SUMMARY.LOG

         Apparent peak=299.28MFLOPS
         Apparent peak=327.75MFLOPS
      This gave performance of 157.20MFLOPS (52.53% of apparent peak)
      This gave performance of 186.68MFLOPS (56.96% of apparent peak)
      This gave performance of 161.51MFLOPS (53.97% of apparent peak)
      This gave performance of 190.77MFLOPS (58.21% of apparent peak)

For PGCC/EGCS I get:

         Apparent peak=499.79MFLOPS
         Apparent peak=499.79MFLOPS
      This gave performance of 355.84MFLOPS (71.20% of apparent peak)
      This gave performance of 416.01MFLOPS (83.24% of apparent peak)
      This gave performance of 379.84MFLOPS (76.00% of apparent peak)
      This gave performance of 411.84MFLOPS (82.40% of apparent peak)

Both runs were on the same 500MHz PIII, using Atlas3.0 beta with no patches.

For Portland I compiled with -O3. 
For PGCC/EGCS I used the default config flags which are : 
		-funroll_all_loops -O3 -fomit-frame-pointers




More information about the Beowulf mailing list