could someone say me an reliable info how many triangles per

second (or milisecond) are menagable by todays graphics api

to be rasterized on the screen?

But I would to know not any way theoretical value but simple practical

one (for example you got simple array of one milion triangles that describes some mesh - how much time it will take for example to rasterize it)

Also doeas anybody know how many triangles per milisecong software

rasterization can do?

could someone say me an reliable info how many triangles per

second (or milisecond) are menagable by todays graphics api

to be rasterized on the screen?

But I would to know not any way theoretical value but simple practical

one (for example you got simple array of one milion triangles that describes some mesh - how much time it will take for example to rasterize it)

Also doeas anybody know how many triangles per milisecong software

rasterization can do?

today that really depends on your shaders and the size of the triangles, amount of overdraw, etc.

Todays graphics APIs don't really care how many triangles you use(triangle data are stored in buffers on the GPU and the API only sends a buffer id to the GPU, it doesn't matter if it is 1 triangle or 1 billion triangles from the APIs point of view). (The APIs care about things like draw calls, state changes, etc).

a modern GPU can handle several billion triangles per second in theory. in practice a few hundred million per second shouldn't be a problem in the normal case.

You sure that more than 100 Milion traingles? How many

it should be possible to test..

I mean working example, I know it differs but take some

example and you could measure it

for example one milion triangles mesh (very detailed plant, bunny or something) (one milion triangle mesh is high but i think it is reasonable) thing should take an array of floats

weighting a 36 MB - how many milisecond it will be taking

to flush it?

I am quite sure that it should take far less than one

second, but do not know much more.. Maybe it would

be comparable to RAM read/write speed which in

practice I think is somewhat more than 1GB/s

(think few GB/second but also I am not sure exact values - doeas anybody know that?, but i am asking also about just practical and no oversized values here)

So assuming 1MB/ms flushing it through pipeline should be "about" 36 milisecond (few times worse?) - but I would like to get some 'field' tests and results, here (And cannot measure it myself right now)

It is not meaningless - those examples you give are interesting thing i am asking about

322.287908 FPS 595,595,897 Triangles per second. 3.102816 ms per frame.
790.450921 FPS 710,755,419 Triangles per second. 1.265101 ms per frame.
728.731499 FPS 101,038,645 Triangles per second. 1.372248 ms per frame.
709.486340 FPS 72,470,738 Triangles per second. 1.409470 ms per frame.

This 500 700 values seem high to me 100 70 would

be more i would be expecting..

Has your scene about 2M of triangles? Why do you think,

you got such speedups and slowdowns? I would like to see

a results in miliseconds with heavier load of triangles, especialy with some screen contained mesh so no tu much

frustrum clipping would occur...

Why do you think, you got such speedups and slowdowns? I would like to see

Because I am drawing different models or looking at the same model from a different direction etc.
One model has 300,000 triangles, drawn in multiple passes per frame (1 ambient, 1 shadow generation, 1 lighting pass), adding up to 710,000,000 triangles per frame at 790 FPS.

On the other hand one of the models is just a little guy with perhaps 15,000 total triangles. No matter how furiously I draw (number of lights, shadows, etc.) him I only get 72,470,738 triangles per second, and cannot possibly catch up to the car with 300,000 triangles rendered only 3 times per frame.


So I am trying to say that triangles-per-second is a useless measurement.


L. Spiro

but this is not.. i want to know example values - generalising the outcome could be nonsense but the concrete measure test is not

I didnt understood the above about triangles - I would be interesting in simple one pas and flat shading - could you

say how much triangles you scene have and what frame times it take to flush it? 300 000 triangles in 3 ms ?

but this is not.. i want to know example values - generalising the outcome could be nonsense but the concrete measure test is not

The question is impossible to answer in a meaningful way. A few points:

• Any figure given is not very authorative since the performance difference between a mobile card, entry level, or a two year old enthusiast card and the latest enthusiast card may very well be 5-20x, depending on what cards you compare and what you measure.
• Depending on the complexity of the vertex shader and other details (geom shader, tesselation) the same card may be able to process 100 or 1000 times as many triangles as in a different setup.
• A "typical" 1080p screen has little over 2 million pixels. Drawing 100 million triangles means you have at least 50x overdraw (best possible case, with pixel-sized triangles -- otherwise you have a lot more). Since GPUs are able to process more triangles than there are pixels on the screen, it is somewhat useless to worry how many they can process.
• Many triangles are not necessarily better than fewer triangles. Processing more triangles quickly results in diminuishing returns. Pixel-sized triangles are a crazy abuse of the pixel shading pipeline due to 2x2 quad processing, and there is no visible improvement (but there may be aliasing effects!).
• ALU >> TEX >> BW >> ROP. You are nowadays almost always ROP-bound. If you aren't, you are bandwidth-bound. The ALU/ROP ratio is about 10x higher nowadays than it was a decade ago [source].