graphics benchmarks (was: questions)

Jecel Assumpcao Jr jecel at
Fri Jun 27 23:59:51 UTC 2003

On Friday 27 June 2003 07:09, Steve Dekorte wrote:
> On Thursday, June 26, 2003, at 10:19 AM, Jecel Assumpcao Jr wrote:
> > [GPU will look more and more like CPU as time goes by]
> If this is true, it should be easy for you to implement some sample
> code that demonstrates the CPU rendering at the speed of the graphics
> card just as I've provided sample code to test OpenGL.

But the graphics card doesn't have a processor, it has dozens of them. I 
would need a system with dozens of CPUs for a fair comparison. Please 
wait about two months...

> How about just a Self version of that one page C program I posted
> earlier?

X Windows only renders 2D polygons in a flat color. The only way to get 
the same image you did is to draw the polygons pixel by pixel. Since 
Self's color management system is a very heavy weight one, I would be 
hardly surprised to get one polygon every few seconds.

There is something very strange in your benchmark - you draw each 
polygon exactly on top of the previous one. How does the z-buffer 
comparison turn out in this case? If it decides the new polygon is in 
front, then you will get what you expect. If it decides it is behind 
then nothing will be drawn (though the image will look right since the 
two polygons are the same) and your results will be very inflated. 
Since you only got about 1 million pol/sec I guess the first case was 

> > But it is X's rendering engine, so I am not sure what we would
> > learn from this little experiment.
> If it turns out that technology X renders 100x slower than technology
> Y, and we're using X and having what we hope are rendering
> performance problems, then we might consider giving Y a try.

By "X" I meant "X Windows".

I would love an OpenGL Self or even just knowing where the bottlenecks 
are. Who knows where the time goes? Unfortunately this is not a trivial 
project and everyone is busy with other things.

Adding OpenGL bindings to Self should be easy enough with the primitive 
maker. You wouldn't need any integration with Morph just to run some 
tests. None of my own machines does a good job with OpenGL, however, so 
there isn't a point in me trying this.

-- Jecel

More information about the Self-interest mailing list