Hi all

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

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

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Display()

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{

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time1 = time();

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cudaEventRecord(record1);

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RunCuda();

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cudaEventRecord(record2);

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time2 = time();

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

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time3 = time();

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}

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then define:

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cudaTimebyTime = time2-time1;

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cudaTimebyEvent = record2-record1;

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cgTime = time3-time2;

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then I find this:

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

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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

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(cudaTimebyTime - cudaTimebyTime).

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

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