Mac mini is slow when connected to local network

2

I have a very specific problem. I work in the AV industry and together with my band we are preparing a concert this weekend.

We have the following setup.

  1. FritzBox for wifi and DHCP
  2. Mac Mini 2018 model with TeamViewer Server for show playback
  3. Two or three Macbooks for remote access
  4. iPads and a digital audio mixing console...

This setup used to work fine but we had some wifi problems (weak reception) so we upgraded the FritzBox to a newer model. Wifi was fine but when we connected the Mac mini via ethernet to the network it slowed down significantly. We checked with a local monitor that it was in fact the Mac itself not the TeamViewer transmission. This pheonmenon is reproducible and immediately starts when connection to the new FritzBox and stops after disconnecting. As soon as we unplug the ethernet connection speed on the Mac Mini is restored. CPU performance is eaten by the Mac OS itself not by any third party software.

We used an old FritzBox beforehand and had no problems. I did the exact same setup on both devices. Then we tried the old FritzBox again and there were no problems.

What might be causing this?

Random facts for trouble shooting:

  • The problem persists even with TeamViewer completetly stopped and with local screen attached.
  • We have no internet connection on the network.
  • We disconnected everything but the Mac Mini, the Fritzbox and one Macbook and the problem still persists.

Some background information: The Mac Mini is used together with Ableton Live for keyboard synthesizers and drum triggers. We have a local network with several network devices (mixing desk, wireless microfones) but those were unplugged for testing.

Max

Posted 2019-04-18T11:07:54.650

Reputation: 121

Things to try - A new admin account; Direct connection, ethernet to ethernet using locally-assigned addresses; Apple's own RDC [or even the free Screen Sharing] rather than TV which may be trying to find a non-existent internet; A full, clean OS install [may be more trouble than it's worth]. – Tetsujin – 2019-04-19T11:15:53.180

@Tetsujin Thank you for your input. Forgot to mention that the problem persists with TeamViewer completely stopped and a direct ethernet connection between the mac mini, fritzbox and the macbook. But then: We changed the FritzBox to a newer model and when we change back to the old one it works again. I don't understand what might be happening there. – Max – 2019-04-19T11:19:14.103

Then I'm tempted to say it's the FritzBox itself - I'd Google "bufferbloat" & the model number, see what you can find. – Tetsujin – 2019-04-19T12:05:19.030

No answers