BenchmarkSyncChanRTT-4           5000000               350 ns/op
BenchmarkBufChanRTT-4            5000000               352 ns/op
BenchmarkBufChanAXRXRTT-4        3000000               407 ns/op
BenchmarkNetPipeRTT-4            2000000               938 ns/op
BenchmarkNetPipeRTTsr-4          1000000              1594 ns/op	<-- here
BenchmarkTCPlo-4                  300000              4814 ns/op
BenchmarkTCPlosr-4                100000             12261 ns/op	<-- here
BenchmarkLinkNetPipeRTT-4         500000              3017 ns/op
BenchmarkLinkTCPRTT-4             100000             15650 ns/op

the δ beetwen TCPlo + serveRecv style RX and full link over TCPlo is ~ 3μs.

-> need to find out why TCPlosr = TCPlo + 8μs