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miminawewe

OpenGL how fast is opengl?

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How many polygons(triangles) can opengl render without using the vertex buffer or display lists to optimize the rendering.Assume no lighting calculations, no fog or other calculations like shadows etc, texturing is taking place, the graphics card is on the main board(S3-graphics adapter), 1.7GH celeron processor, 256MB memory. I tested and got about 75,000 triangles/sec is this right? If there are such opengl statistics on the web please point them to me. Thank you.

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It entirely and completely depends on your graphics card and driver. It's like asking "how long is a piece of string".

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If you're not doing any batching of triangles, but just draw using immediate mode, the throughput will be very low indeed.
Why would you want to do this?

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Quote:
Original post by Fruny
It entirely and completely depends on your graphics card and driver.

And CPU speed + bus bandwidth, especially for immediate mode (which is extremely CPU heavy, and has to retransfer data to the card every frame).

Quote:

the graphics card is on the main board(S3-graphics adapter),

Do you actually have hardware OpenGL support on that ? Make sure you aren't running in software.

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Quote:
Original post by miminawewe
the graphics card is on the main board(S3-graphics adapter), 1.7GH celeron processor, 256MB memory. I tested and got about 75,000 triangles/sec is this right?


This is right for a non-3D accelerated graphics card. You're likely using the Microsoft software emulation which is entirely dependant on your CPU speed. Do not expect any good performance (or any performance at all) with software emulation.

Y.

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I've done some research and I realize I should have asked whether there is an opengl profiler available for free that I can download from the web.

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Quote:
Original post by Yann L
Quote:

the graphics card is on the main board(S3-graphics adapter),

Do you actually have hardware OpenGL support on that ? Make sure you aren't running in software.


I think my S3 Trio claimed it was doing coordinate transformations in hardware... T&L were definitely software.

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Quote:
Original post by miminawewe
How many polygons(triangles) can opengl render without using the vertex buffer or display lists to optimize the rendering.Assume no lighting calculations, no fog or other calculations like shadows etc, texturing is taking place, the graphics card is on the main board(S3-graphics adapter), 1.7GH celeron processor, 256MB memory. I tested and got about 75,000 triangles/sec is this right? If there are such opengl statistics on the web please point them to me.
Thank you.


[google]

glxcess

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Quote:
Original post by Fruny
It entirely and completely depends on your graphics card and driver. It's like asking "how long is a piece of string".


7 cm.
And OpenGL has a max speed of 187 m/s.

Seriously though, if you get 75k triangles with your code and your hardware, then that is exactly how fast OpenGL is under those circumstances. OpenGL can be very slow indeed if you use it wrong. It can also be pretty damn fast, if you use it right. A profiler isn't required for this, just a basic understanding of what actually happens under the hood.

(Of course, as was said, I really doubt your S3 card has much hardware acceleration at all, which kinda limits what you can do, with or without OpenGL.

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