lonteviro, the numbers are in bytes / sec.
I witnessed some peaks at 15 MB/sec like you, but this was more or less random and did not seem to depends on the version of the node.
Another wierd thing that I saw (i was not able to reproduce it) is that while downloading the blocks, a ping/pong exchange in the middle took 4 seconds.
This is normal, the messages sent from the node to the client are queued in bitcoind.
If client ask 10 000 blocks then does 1 ping, then the pong of the server will be queued at the end of the 10 000 blocks.
This is also why the pong timeout is 20min in bitcoind.
Did you tested on a local node ? your results are very coherent with mine.
I notice no bottleneck of disk IO or CPU. The socket buffer being never full means that NBitcoin is processing blocks faster than they are coming from bitcoind.
Did someone managed (on any library) to fetch block from a local node at a highest speed than 10MB/s ?
