Unexplained performance difference for same kernels

Hi HRZ,I edited my post above, there was a mistake where it was not temp[-1], but it was temp[i].also I'm just calculating the time it takes to run the kernel, not data transfer. Here is the way I calculate FLOPS: flops = [[num_of_work_items] * [num_ops_per_kernel] * [num_flops_per_ops] * [stream_size_of_vars]] / total time.For example for first kernel the flops would be something like => flops = [(around 1Mil) * 32 * 1 * 16] / total_time.Am I doing something wrong here?