c++ - Winsock client latency not proportional to server latency -

c++ - Winsock client latency not proportional to server latency -

i have winsock client sends 1gb of info winsock server in chunks of 4mb. client , server application utilize library built on top of winsock2 , uses iocp threads.

for each of 4mb transfers, server work , sends response client.

the client sends 256 such 4mb requests using overlapped socket io.

the problem: when dowork() on server returns immediately, whole process takes 9 seconds complete; when dowork() takes 500ms, whole 1gb transfer process takes whooping 130 seconds!

shouldn't client latency proportional server latency? is, if server takes 500 ms job, shouldn't whole process have completed in 9.5 seconds? potential bottlenecks causing disproportionate increment in running time?

c++ networking asynchronous network-programming winsock2