Quick tip for Linux Intel Fortran users

Discussion on computers, ROMS installation and compiling

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rsignell
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Quick tip for Linux Intel Fortran users

#1 Post by rsignell » Wed Aug 10, 2005 8:04 pm

Want to compile ROMS faster with little affect on the run time?

Ruoying He heard me complain about the length of time ROMS 2.2 was taking to compile on my Linux box with the Intel Fortran Compiler (5 minutes using *both* of my 3Ghz Zeon Processors!) and told me to compile with "-O2" instead of "-O3". He said -O2 compiles nearly twice as fast -O3 with little or no difference in the run time of the code. I tried it on my Adriatic simulations, and he was right: 200% faster compilation, and only 1% slower simulation!

-Rich

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wilkin
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#2 Post by wilkin » Mon Aug 15, 2005 2:06 pm

Did -O2 and -O3 give exactly the same result?
Just curious.

John
John Wilkin: DMCS Rutgers University
71 Dudley Rd, New Brunswick, NJ 08901-8521, USA. ph: 609-630-0559 jwilkin@rutgers.edu

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