Thanks for the suggestions - I'll need to do some more experimentation when
I get back in the office, but I think you're on to something, perhaps with
the router at Location B in my examples.    I did a straight UDP speed test
with iperf3, and that worked fine - over 500Mbit/sec - there shouldn't be
anything funny with MTU going on, nor any IPv6... however I did two
additional tests:

At my main location, I've got another "low end" box on the same local
network as the "server" - this one is an intel Atom CPU - with that I was
able to get about 585Mbit/sec (compared to the 930-940 without wireguard).


I've got a 3rd location available - actually a low end VM on AWS - this one
gets around 300Mbit unencrypted, and actually tested above that via
wireguard - I assume thats just normal fluctuation, but seems to point the
finger to something specific at location B, my office.    I'll continue to
investigate and update if I figure anything out... it'll probably be at
least a week before I get anywhere though, due to work travel.

Thanks again,
Scott


On Fri, Mar 1, 2019 at 5:18 AM Kalin KOZHUHAROV <me.kalin@gmail.com> wrote:

> On Fri, Mar 1, 2019 at 11:11 AM Scott Lipcon <slipcon@gmail.com> wrote:
> >
> > I've been experimenting a bit with Wireguard on several ubuntu systems,
> and am not seeing the performance I'd expect based on the numbers at
> https://www.wireguard.com/performance/
> >
> > I'm wondering if there is a configuration setting i'm missing or any
> better way to debug this.
> >
> > Testing between two locations - both have nominally 1Gbit internet
> connections from the same provider.
> >
> > At location A:
> > 1) Ubuntu 18.04 "server" - i7-4790K CPU @ 4.00GHz
> > 2) Ubuntu 16.04 client - i5-3470 CPU @ 3.20GHz
> >
> > At location B:
> > 3) Ubuntu 18.04 client - Celeron N2808  @ 1.58GHz
> > 4) Ubuntu 18.04 client - Virtual Machine - Xeon(R) Gold 6126 CPU @
> 2.60GHz
> >
> >
> > Using iperf3 for all tests, with 8 threads, but that doesn't seem to
> matter significantly.
> >
> > Between 1 & 2, via gigabit LAN - 940 Mbit/sec.
> > Between 1 & 2, via WireGuard - 585 Mbit/sec
> > - I might have expected a bit higher, but this is certainly acceptable.
> >
> > Between 3 and 1, direct iperf3 - 580 Mbit/sec
> > Between 3 and 1, WireGuard - 73 Mbit/sec
> >
> > At this point I was guessing WireGuard was CPU limited on this little
> Celeron, so I set up the Xeon VM (#4):
> >
> > Between 4 and 1, direct iperf3 - ~600 Mbit/sec
> > Between 4 and 1, WireGuard - 80 Mbit/sec
> >
> > In other words, the much faster VM is only a tiny bit faster that the
> celeron.
> >
> > Any suggestions?
>
> A lot can go wrong speed-wise "on the Internet"...
>
> What sits in between those hosts that you have control of (routers,
> switches, firewalls...)?
> IPv6 involved at all?
> ISP having throttling policy for "UDP we don't understand"?
> Play with the MTU, you might be hitting some fragmentation issues that
> a weak router is not handling fast enough.
> Play with Wireshark (new 3.0 even has support for wireguard
> protocol!), capture some traffic, look for any transmission errors.
>
> Cheers,
> Kalin.
>