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[sienaiwun]

Hi all

I would like to know the exact time measurement for cg shader.

Now I have a display function containing two parts : cuda part computing data, and cg shader render the scene. Like the following :

Display()

{

time1 = time();

cudaEventRecord(record1);

RunCuda();

cudaEventRecord(record2);

time2 = time();

cgRender(); //in cgRender render the scene dozens of time.

time3 = time();

}

then define:

cudaTimebyTime = time2-time1;

cudaTimebyEvent = record2-record1;

cgTime = time3-time2;

then I find this:

cudaTimebyTime != cudaTimebyEvent , which means cudaEvent's time measurement is different from the time() function.

what's more, when I change cg function in cgRender(); (cudaTimebyTime - cudaTimebyTime) changes rather than the cgTime. It seems cgTime only records the scene drawing time while cg time measurement parts records in

(cudaTimebyTime - cudaTimebyTime).

Can it be true and what's the reason, how should I record the cg time measurement.