Hi All,
So I tried the following:
AMBER 11 with and without the fix for FOPTFLAGS in the Makefile.
Original Makefile (PMEMD_OPTFLAGS)
-----------------
Compiler States Vectorization at link? JAC benchmark time
(s)
-------- -----------------------------
----------------------
gfortran 4.1.2 N/A 178.15
ifort 10.1.018 Yes 155.60
ifort 11.0.084 Yes 149.33
ifort 11.1.056 No 149.30
ifort 11.1.069 No 150.40
New Makefile (PMEMD_FOPTFLAGS)
------------
Compiler States Vectorization at link? JAC benchmark time
(s)
-------- -----------------------------
----------------------
gfortran 4.1.2 N/A 178.80
ifort 10.1.018 Yes 152.94
ifort 11.0.084 Yes 150.54
ifort 11.1.056 No 149.85
ifort 11.1.069 No 150.36
So from what I can see this is fortunately largely cosmetic, or at least it
only affects certain very specific Intel compiler versions or possibly
specific Intel chips. Either way we should probably issue a bugfix for it
and replace the 3 occurrences of PMEMD_OPTFLAGS with PMEMD_FOPTFLAGS. It
looks like it still works fine with gfortran.
Dave, what version of ifort were you using and what is the difference in
timings? Do you see the words:
ipo: remark #11000: performing multi-file optimizations
ipo: remark #11005: generating object file /tmp/ipo_ifort8APlbU.o
at link time?
All the best
Ross
/\
\/
|\oss Walker
---------------------------------------------------------
| Assistant Research Professor |
| San Diego Supercomputer Center |
| Adjunct Assistant Professor |
| Dept. of Chemistry and Biochemistry |
| University of California San Diego |
| NVIDIA Fellow |
|
http://www.rosswalker.co.uk |
http://www.wmd-lab.org/ |
| Tel: +1 858 822 0854 | EMail:- ross.rosswalker.co.uk |
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Received on Sat Aug 28 2010 - 07:00:04 PDT
