> Currently I'm using "unbuffered" send mode as in my case it > surprisingly provides twice as high throughput as "buffered" one. > Though, I initially expected that "buffered" send mode should have > better performance compared to "unbuffered" one
It should not be faster. I suspect that is some artifact of a bad "buffered configuration" It blocks waiting for ACKs and when communicating with RFC 1122 peers it cannot send packets faster than twp per second. The application is also blocked and can do nothing until the ACKs are received. So any possible performance benefits from concurrent operation is lost. It is generally not a very good implementation without buffering.
