Re: [ccp4bb]: CCP4 - Pentium - Again

[Nat <nathaniel.echols@yale.edu>]

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> Depending on what you're doing, you can in very rare circumstances get
> extremely good speed improvements using the intel compiler - I have had as
> much as a factor of 2.5 in execution speed between gcc 2.95.3 and icc 6 -
> however, I have heard that gcc3.1 will give similar speed improvements in
> these situations.

Compiling with '-O2 -tpp7 -xK' should produce the best code for Pentium 4,
though I suspect the binaries won't work very well on other machines.
There are other weirder optimization flags but I'm not sure what these do
yet.  However, '-O3' causes the Fortran compiler to choke on some code
(specifically parts of CNS) when it tries to vectorize loops.

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Nathaniel Echols                                                  Programmer
nat@bioinfo.mbb.yale.edu                                        Gerstein Lab
203-589-6765                                                 Yale University
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