Data Structures and Algorithms

The only think that TCP_NODELAY does is disabling packet batching/merging through Naggle's algorithm. Supposedly that increases throughput by reducing the volume of redundant information required to send small data payloads in individual packets, with the tradeoff of higher latency. It's a tradeoff between latency and throughput. I don't see any reason for transfer rates to lower; quite the opposite. In fact the very few benchmarks I saw showed exactly that: TCP_NODELAY causing a drop in the transfer rate.

There are also articles on the cargo cult behind TCP_NODELAY.

But feel free to show your data.