Learn how easy it is to sync an existing GitHub or Google Code repo to a SourceForge project! See Demo

Close

#114 Slow loops and where execution

closed
nobody
None
5
2011-10-19
2011-09-21
ajheaps
No

GDL 0.9.1 compiled from source for OpenSUSE 11.3 64 bit gives slow loops and where execution relative to IDL 8.0.1.

See attached program for example code. On my server running sw, 1000 gives the following times:

GDL: loops=1.03 where=0.0686
IDL: loops=0.146 where=0.00313

The results are the same so GDL agrees with IDL so that's good but the speed of execution considerably slower in GDL.

Discussion

  • ajheaps
    ajheaps
    2011-09-21

     
    Attachments
  • Alain C.
    Alain C.
    2011-09-22

    Thanks for the report.
    we know that the GDL "loop" way is much slower than the IDL
    but, on various systems, I have a ratio 2 to 4 between GDL and IDL 6, 7 or 8
    (clear progress for IDL 7 compared to IDL 6). You show a factor 20 ?!

    Do you have the OpenMP flag on ? Could you try with the current CVS version ?
    (I remember we delivered a version with -O2 with CMake way)

    I consider this is not really a bug.
    For sure, it would be great to be better, help welcome !

    (in the time_test3, one significant part of slow comes from SMOOTH, help welcome !)

     
  • Alain C.
    Alain C.
    2011-09-22

    another bad new for us: I found that, on the same computer, the current version of WHERE
    is significant slower than a "well packed/tested" previous one :(

    Alain

     
  • Marc Schellens
    Marc Schellens
    2011-10-10

    The latest CVS addresses the decay in speed with OpenMP.
    Furthermore array indexing (responsible for the execution time in sw.pro) works now significantly faster. Please check it out.

     
  • ajheaps
    ajheaps
    2011-10-11

    The latest cvs is much faster with loops - around 85% faster! Nice :-)

     
  • ajheaps
    ajheaps
    2011-10-11

    My previous comment about how fast loops are was a little crypic. The speedup for loops in more conventional terms is 6.2x as fast as the previous CVS release. A major improvement!

     
  • Alain C.
    Alain C.
    2011-10-19

    • status: open --> closed
     
  • Alain C.
    Alain C.
    2011-10-19

    very significant progress have been made during last weeks, see CVS.
    (we are cleaning the code, and also OSX version is pendant)

    please report on a separated bug report clear differences (with sample code) in speed
    between IDL and GDL. (we know SMOOTH is slow ;-)

    Alain