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Re: abysmally low scp performance

Edgar Fuß <> writes:

> I'm just scp-ing a multi-gigabyte file from one NetBSD-8 machine to another, 
> and get a whopping 10MB/s throughput.
> Interfaces are wm, 1000BaseT (says ifconfig and the switch), connected to 
> the same (enterprise) switch.
> Discs are ~20% busy on the receiving end, less on the sending end.
> ssh/sshd are at ~20% CPU max, CPUs are 50% (sending side, which does multiple 
> other things)/80% (receiving side, which does nothing) idle.

That's 80 Mb/s.

1. install iperf3 and run that.  That takes ssh and disks out of the
equation.  Maybe try iperf2 also.

2. run netstat -s (on both machines) before and after the test, and diff

3. receive cpu usage seems high.  watch it while iperf is running.
could be crypto bound in ssh.

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