[vtk-developers] (no subject)

[Prabhu Ramachandran]

Hi,

>>>>> "KM" == Ken Martin <ken.martin at kitware.com> writes:

    KM> Hello Folk, I just bumped into a significant performance
    KM> change for some cases. I added a new test called TimeRenderer2
    KM> that creates lighted triangle strips and renders them. I was

<snip>

    KM> faster which I expected. What suprised me is that the
    KM> subsequent renders ran at 35 million triangles per second on
    KM> an old gforce256. Apparently the display list generated is
    KM> different if it is created in GL_COMPILE versus
    KM> GL_COMPILE_AND_EXECUTE even though I would think they would be
    KM> the same. I have checked in this change so we will see if
    KM> everything works with it. Hopefully other folks will see
    KM> faster rendering startups and rates. I have no idea if similar
    KM> sppedups will happenon UNIX systems but it is quite
    KM> possible. Hank Childs suggested that the display list building
    KM> was too slow and www.opengl.org said... (note the last item)

Here are the results of running sphere-bench before and after your
modifications.

Before your modifications

--------------------------------------------------
Best results, summary :
  - i686 running Linux 2.2.18
  - VTK 4.0.0 (rev: 1.1036, 2001/10/25 08:12:07)
  - OpenGL
  - Visual is 1024x768, truecolor/truecolor/16
  - Tcl/Tk 8.3.3
  - window was 400 x 400
   1) 256x256 :  361.0 kpolys/s : [stripper]
   2) 256x256 :  172.5 kpolys/s : []
   3) 256x256 :  172.1 kpolys/s : [transparency]
   4) 256x256 :  171.9 kpolys/s : [small_sphere]
   5) 256x256 :  143.9 kpolys/s : [texture]
   6) 256x256 :  135.4 kpolys/s : [texture, transparency]
   7) 256x256 :   84.5 kpolys/s : [wireframe]

------- DONE (in 303 sec.) -------

After updating and recompiling my sources.

--------------------------------------------------
Best results, summary :
  - i686 running Linux 2.2.18
  - VTK 4.0.0 (rev: 1.1039, 2001/10/28 09:13:24)
  - OpenGL
  - Visual is 1024x768, truecolor/truecolor/16
  - Tcl/Tk 8.3.3
  - window was 400 x 400
   1) 256x256 :  672.8 kpolys/s : [stripper]
   2) 256x256 :  233.7 kpolys/s : [transparency]
   3) 256x256 :  233.4 kpolys/s : [small_sphere]
   4) 256x256 :  232.1 kpolys/s : []
   5) 256x256 :  207.4 kpolys/s : [texture, transparency]
   6) 256x256 :  205.2 kpolys/s : [texture]
   7) 256x256 :  119.5 kpolys/s : [wireframe]

------- DONE (in 261 sec.) -------

So there is _definitely_ improvement on Linux.  The numbers you see
aren't so great since I don't have obscene hardware like some
others. <grin> 

I am using a TNT2 M64 with 32MB RAM and am running XFree86 4.1.0 with
nVidia's accelerated drivers and OpenGL.  I was also running a CPU
intensive process in the background
(http://foldingathome.stanford.edu) but the process has a priority (a
nice value) of 19 and it was running during both tests.


Cheers,
prabhu

-- 
Prabhu Ramachandran			  MayaVi Data Visualizer
http://www.aero.iitm.ernet.in/~prabhu     http://mayavi.sf.net

Where there's no emotion, there's no motive for violence.
		-- Spock, "Dagger of the Mind", stardate 2715.1