Well, here's just one measurement using iperf 2.0.12. All clocks are synchronized to a GPS disciplined oven controlled oscillator (OCXO). Connected via 1Gbs. FreeBSD latency is significantly better.
Source fedora 28 xeon machine, receivers FreeBSD 11.1 and Fedora 25 (same brix platform) connected via a Cisco 300 switch.
RX:
FreeBSD:
root@zeus:/usr/local/src/iperf2-code # iperf -s -u -e --udp-histogram=10u,100000 --realtime
------------------------------------------------------------
Server listening on UDP port 5001 with pid 53703
Receiving 1470 byte datagrams
UDP buffer size: 41.1 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.100.34 port 5001 connected with 192.168.100.55 port 52536
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Latency avg/min/max/stdev PPS
[ 3] 0.00-10.00 sec 1.25 MBytes 1.05 Mbits/sec 0.004 ms 0/ 892 (0%) 0.086/ 0.060/ 0.150/ 0.014 ms 89 pps
[ 3] 0.00-10.00 sec T8(f)-PDF: bin(w=10us):cnt(892)=7:160,8:143,9:181,10:159,11:242,12:6,16:1 (5/95%=7/11,Outliers=0,obl/obu=0/0)
Fedora 25:
[root@hera iperf2-code]# iperf -s -u -e --udp-histogram=10u,10000 --realtime
------------------------------------------------------------
Server listening on UDP port 5001 with pid 16669
Receiving 1470 byte datagrams
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.100.33 port 5001 connected with 192.168.100.55 port 35894
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Latency avg/min/max/stdev PPS
[ 3] 0.00-9.99 sec 1.25 MBytes 1.05 Mbits/sec 0.010 ms 0/ 892 (0%) 0.261/ 0.098/ 0.319/ 0.021 ms 89 pps
[ 3] 0.00-9.99 sec T8(f)-PDF: bin(w=10us):cnt(892)=10:1,21:1,23:6,24:107,25:141,26:209,27:151,28:124,29:81,30:47,31:19,32:5 (5/95%=24/30,Outliers=0,obl/obu=0/0)
TX:
[root@rjm-clubhouse-28 rjmcmahon]# iperf -s -e -u --udp-histogram=10u,100000 --realtime
------------------------------------------------------------
Server listening on UDP port 5001 with pid 26016
Receiving 1470 byte datagrams
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.100.55 port 5001 connected with 192.168.100.34 port 20343
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Latency avg/min/max/stdev PPS
[ 3] 0.00-10.01 sec 1.25 MBytes 1.05 Mbits/sec 0.010 ms 0/ 893 (0%) 0.094/ 0.064/ 0.476/ 0.023 ms 89 pps
[ 3] 0.00-10.01 sec T8(f)-PDF: bin(w=10us):cnt(893)=7:12,8:38,9:291,10:311,11:198,12:28,13:10,14:1,15:1,42:1,45:1,48:1 (5/95%=8/11,Outliers=3,obl/obu=0/0)
[ 4] local 192.168.100.55 port 5001 connected with 192.168.100.33 port 58391
[ 4] 0.00-10.00 sec 1.25 MBytes 1.05 Mbits/sec 0.013 ms 0/ 892 (0%) 0.079/ 0.048/ 0.127/ 0.009 ms 89 pps
[ 4] 0.00-10.00 sec T8(f)-PDF: bin(w=10us):cnt(892)=5:1,6:10,7:115,8:265,9:425,10:51,11:18,12:3,13:4 (5/95%=7/10,Outliers=0,obl/obu=0/0)
Source fedora 28 xeon machine, receivers FreeBSD 11.1 and Fedora 25 (same brix platform) connected via a Cisco 300 switch.
RX:
FreeBSD: root@zeus:/usr/local/src/iperf2-code # iperf -s -u -e --udp-histogram=10u,100000 --realtime ------------------------------------------------------------ Server listening on UDP port 5001 with pid 53703 Receiving 1470 byte datagrams UDP buffer size: 41.1 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.100.34 port 5001 connected with 192.168.100.55 port 52536 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Latency avg/min/max/stdev PPS [ 3] 0.00-10.00 sec 1.25 MBytes 1.05 Mbits/sec 0.004 ms 0/ 892 (0%) 0.086/ 0.060/ 0.150/ 0.014 ms 89 pps [ 3] 0.00-10.00 sec T8(f)-PDF: bin(w=10us):cnt(892)=7:160,8:143,9:181,10:159,11:242,12:6,16:1 (5/95%=7/11,Outliers=0,obl/obu=0/0)
Fedora 25: [root@hera iperf2-code]# iperf -s -u -e --udp-histogram=10u,10000 --realtime ------------------------------------------------------------ Server listening on UDP port 5001 with pid 16669 Receiving 1470 byte datagrams UDP buffer size: 208 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.100.33 port 5001 connected with 192.168.100.55 port 35894 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Latency avg/min/max/stdev PPS [ 3] 0.00-9.99 sec 1.25 MBytes 1.05 Mbits/sec 0.010 ms 0/ 892 (0%) 0.261/ 0.098/ 0.319/ 0.021 ms 89 pps [ 3] 0.00-9.99 sec T8(f)-PDF: bin(w=10us):cnt(892)=10:1,21:1,23:6,24:107,25:141,26:209,27:151,28:124,29:81,30:47,31:19,32:5 (5/95%=24/30,Outliers=0,obl/obu=0/0)
TX:
[root@rjm-clubhouse-28 rjmcmahon]# iperf -s -e -u --udp-histogram=10u,100000 --realtime ------------------------------------------------------------ Server listening on UDP port 5001 with pid 26016 Receiving 1470 byte datagrams UDP buffer size: 208 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.100.55 port 5001 connected with 192.168.100.34 port 20343 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Latency avg/min/max/stdev PPS [ 3] 0.00-10.01 sec 1.25 MBytes 1.05 Mbits/sec 0.010 ms 0/ 893 (0%) 0.094/ 0.064/ 0.476/ 0.023 ms 89 pps [ 3] 0.00-10.01 sec T8(f)-PDF: bin(w=10us):cnt(893)=7:12,8:38,9:291,10:311,11:198,12:28,13:10,14:1,15:1,42:1,45:1,48:1 (5/95%=8/11,Outliers=3,obl/obu=0/0) [ 4] local 192.168.100.55 port 5001 connected with 192.168.100.33 port 58391 [ 4] 0.00-10.00 sec 1.25 MBytes 1.05 Mbits/sec 0.013 ms 0/ 892 (0%) 0.079/ 0.048/ 0.127/ 0.009 ms 89 pps [ 4] 0.00-10.00 sec T8(f)-PDF: bin(w=10us):cnt(892)=5:1,6:10,7:115,8:265,9:425,10:51,11:18,12:3,13:4 (5/95%=7/10,Outliers=0,obl/obu=0/0)