关于cuda拷贝的速度测试

int main(){
    clock_t start,finish;

    int *d_data,*h_data;
    h_data = (int *)calloc(MAX, sizeof(int));
    memset(h_data,0,MAX*sizeof(int));
    cudaMalloc((void **) &d_data,MAX*sizeof(int));


    start = clock();
    cudaMemcpy(d_data,h_data,MAX*sizeof(int),cudaMemcpyHostToDevice);
    cudaMemcpy(h_data,d_data,MAX*sizeof(int),cudaMemcpyDeviceToHost);
    finish = clock();


    cudaFree(d_data);
    free(h_data);
    cout<<"time is "<<finish-start<<endl;
    getchar();
return 0;
}