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As mentioned in the previous section, in Fig. 9(b), when the
available bandwidth is higher than 3Mbps, the execution time with compression
does not change very much. This result does not comply with the prediction
formulas (2) - (5), which says that
with the decreasing of available bandwidth, transmission time should increase,
finally increasing the total execution time. In this section, we show that this
abnormal results is due to the overlap between network transmission
and local compression on the host. More specifically, if the
computation time is big enough, what really matters for the total execution time
is the socket buffer copying time, not network transmission time.
That is why the network available bandwidth will not affect the application performance.
4 Model the Overlap of Local Computation and Network Execution