[vtkusers] VTK/ParaView and shared libs ...

[Stefan Melber]

Hi,


i noticed an behavior of VTK, which i cant explain at the moment. Maybe, 
someone found the same effect and has some thoughts ...

Ok - what was done:

o compiling ParaView 3.14.1 with QT 4.6.2 on a 64bit linux box
o comparing the Version without and with shared libs (BUILD_SHARED off 
and on)
o starting ParaView and have a look on the loading time / the time for 
the first interaction (e.g. clicking on load-button)
o measure the loading time of an complex case and the time for the 
rendering after a rotation of the (complex) model on the screen
o measurements done with TimerLog of ParaView

What i found was:

        | static          | shared
=====================================
GUI    | ok              | slow
Load   | 7.139 sec.      | 11.47 sec.
Rotate | 0.088 sec.      | 0.029 sec.

The slow GUI response (approx. 3-5 secs) of the shared variant is clear 
because of the loading time of all libs. The same holds for the "Load" - 
however - why is the render time after a rotation more then _two times 
faster as for the static case_?

Further on, these test above was done on a linux box with Quadro4000 
graphics card, 295.33 NVidia driver, SLED-Linux with 3.0.13er kernel and 
Xorg 7.4.

Now, i did the same tests on the same linux box, but with OpenSuse 12.1, 
3.1.10er kernel and Xorg 7.6 and got

        | static          | shared
=====================================
GUI    | ok              | ok
Load   | 7.279 sec.      | 11.28 sec.
Rotate | 0.5 sec.        | 0.028 sec.

Thats now really interesting: In both cases (static and shared) now the 
GUI is fast - why - i dont know. The Loading time is comparable to SLED 
- but the render time of the static case is now about 6 times slower 
then with SLED?! And - it has some unsteady delays in the redraw. The 
shared variant is ok and_again faster then the static one_...

Any ideas why the rendering is faster with shared libs?!

Best regards and thank you,

      Stefan







===============================================================

                      _/          Stefan Melber-Wilkending
                    _/_/          ------------------------
                  _/  _/
          _/_/_/_/_/_/_/_/_/_/     German Aerospace Center
        _/    _/    _/    _/              -- DLR --
      _/    _/    _/    _/              Member of the
    _/_/_/_/_/_/_/_/_/_/            Helmholtz-Association
          _/  _/  _      _
          _/_/   | \ |  |_|       Institute of Aerodynamics
          _/     |_/ |_ | \          and Flow Technology
                                  Transport Aircraft Branch

    Fields of activities:         Lilienthalplatz 7
    o High-Lift Research          D-38108 Braunschweig/Germany
    o Complex Configurations
    o Numerical Wind-Tunnel       Phone ..: +49 531/295-2836
    o Wind-Tunnel Design          Fax. ...: +49 531/295-2914
    o Supercomputing
    o Visualization Techniques    Email ..: Stefan.Melber at dlr.de
    o Glider-Aerodynamics         Web ....: http://www.dlr.de/AS

===============================================================

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