Intel Fortran 7 Compiler

From:Nick Holford Subject:[NMusers] Intel Fortran 7 Compiler Date:Mon, 02 Dec 2002 00:06:42 +1300 FYI, Compaq/HP, the current developer of Visual Fortran, is planning a combined Fortran compiler product with Intel. http://www.intel.com/software/products/compilers/f60/status_update.htm Intel is offering a 30 day free evaluation of Intel Fortran 7 (160 Mbyte download). http://www.intel.com/software/products/compilers/fwin/eval.htm This seems to be a beta testing effort of the Intel Fortran compiler which will be used to merge Compaq Visual Fortran with Intel Fortran. According to various posts on the Intel Fortran Users forum ( http://intel.forums.liveworld.com/forum.jsp?forum=76) current users of Compaq Digital Fortran (Version 6.*) may purchase Intel Fortran 7 for US$200 with a one year upgrade guarantee. This would seem to be a good deal for keeping up with the next version of Visual Fortran. I have done some limited testing of the Intel Fortran compiler (ivf) with NONMEM. Compilation =========== ivf shares a bug/feature with g77 and adds its own problems (which can be worked around). 1. Intermediate output cannot be sent to the DOS con device because it seems the con device is not recognized. Define FNINT as 'nul' instead of 'con' in BLKDAT. g77 behaves the same way. 2. The NONMEM FLU subroutine requires the USE IFLPORT statement in order to use the COMMITQQ procedure. 3. The NONMEM OFILES suboutine cannot open unit 34 because it has already been opened. Comment out the OPEN statement for unit 34. Execution ========= I have run the valfit1 through valfit5 problems distributed some time ago by Peter Bonate. These problems all use the same data but span a range of difficulty for estimation. Some seem to minimize successfully and run the covariance step with any compiler while others usually terminate and even if minimization is successful the covariance step usually fails. I tried several optimization settings and the one that seems to work best (convergence) is /Gs /Ob1gyti /Qprec_div. As far as I can tell there are no direct equivalents of the Compaq df options /fltconsistency /optimize:4 /fast. On a 2 GHz Pentium IV the ivf compiler was generally slower (20% longer per function evaluation). On a 1 GHz Pentium III the ivf compiler took 42% longer per function evaluation (/G6 PIII option). Average run times were 42% longer on the 1 GHz PIII compared to the 2 GHz PIV with df and 65% longer using ivf. Convergence =========== Convergence behaviour on the 2 GHz PIII is summarized below: Converged Covariance Objective df ivf df ivf df ivf valfit1: y y y y 9612 9612 valfit2: n y n n 8280 8564 valfit3: n n n n 7784 7784 valfit4: y y y y 8350 8350 valfit5: n y n n 8350 8350 ivf converges but at a much lower obj on valfit2 ivf converges but df does not (obj is the same) on valfit5 ivf and df were similar on the other problems The behaviour with valfit2 suggests that the df compiler (version 6.6A) may be better because it gets a much lower obj. On the other hand ivf was better with valfit5 (converged) but the obj and parameters were the same as df. The df compiler is substantially faster with the Pentium III CPU. Nick -- Nick Holford, Divn Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x6730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/ _________________________________________