Log in or register to post comments

processing time

May 28, 2013 - 10:11am #1

Hi, 

I have an object that consists of many triangles. Then I compared the rendering processing time with VAO and VBO.

With VAO I got range about  0.05 second < processing time < 0.3 second
But the frame rate is about 2-3 per second

With VBO I got range about 0.0002 second < processing time < 0.03 second

but the frame rate is also about 2-3 per second.

What I'm wondering is why the frame rate does not increase as the processing time of rendering  with VBO decreases?

 

processing time

May 29, 2013 - 11:14am #6

That seems correct, based on your results.

 

processing time

May 29, 2013 - 9:13am #5

Hi,
 

So, can I roughly say that using VBO does not increase the frame rate? because when I measured the consecutive frame as you said, the frame rate did not change significantly.

 

Thanks

processing time

May 28, 2013 - 10:42pm #4

Ok. One reason why you don't see correct numbers for your "processing" time (i.e. not aligned with the observed frame rate) could be that the VBO rendering is done somewhat asynchronously (i.e. it is flushed to the GPU somewhat later), so you cannot capture that.

The only reliable way is to measure the time elapsed between two consecutive frames (i.e. current frame and previous frame)

 

processing time

May 28, 2013 - 9:29pm #3

Hi, 
No, I have checked carefully and I did not include some other computing task. When I tried to reduce half of my triangles I got up to 18 frame rate per sec.
 

Yeah, the processing time I measured is only draw command
 

t0 = clock();
drawObject();
t = clock()-t0;

Then I measured the frame rate by taking measurement of every call to renderFrame method. So according to the frame rate and processing time of draw command that I measured, does it make sense?

processing time

May 28, 2013 - 11:16am #2

Hi, are you doing other time consuming tasks in your app ?

I would recommend to measure the time consumed for the while renderFrame() method and check if you have other parts in your code that also eat time...

The measurements you shared seem to capture only part of the "processing" time

Log in or register to post comments