Delays during isochronous TX on Windows

[Rony Ross]

Hello,

I ran iperf2 2.1.4 on Win10 using:
iperf -c <ip address=""> -u --isochronous=90:100m,0 -i 1 -w 8M -t 30 -e</ip>

I've used Wireshark to capture the traffic and noticed that it took 4-5ms
for iperf to complete each data transfer of ~140KB. Attached is a Wireshark
graph of packets per millisecond.
It seems that for some reason iperf added delay/sleep during the data
transfer

Thanks,
Rony

[Rony Ross]

I've investigated some more, and I'm under the impression that the delay is caused by a heavily loaded CPU. Transmitting 1500B UDP frames is inefficient and the platform that I'm using cannot handle 100Mbps@90fps without adding such delay.