macOS Sierra 10.12.6. and multiple USB keyboards and mice

[Delta Music Belgium]

I'm using a MacPro 5.1 with a lot of powered USB hubs (with a lot of synths connected to them) and also 3 sets of USB keyboards and mice.

I use this system for many years with all Mac OS versions since 10.8.5 without any problem.

Last week I decided to upgrade an SSD to macOS Sierra 10.12.6 and since then only one keyboard and mouse works, the other ones are dead.

Each keyboard also has a LED lamp and when the Mac starts I can see all the LED lamps turn on as normal, but the moment the computer starts to load macOS Sierra 10.12.6 two sets go dead. Once launched I can connect a failing keyboard and mouse to another USB port on a USB hub and it will work again. But after restart macOS Sierra 10.12.6 looses contact again.

Restarting with another OS goes fine, everything always works, starting with macOS Sierra 10.12.6 I loose 2 keyboards and mice.

I tried a lot of things but I'm starting to run out of ideas. Google tells me it is not uncommon for macOS Sierra 10.12.x to have problems with USB, so maybe it's the OS to blame?

Is anyone else experiencing the same problems?

[musicman691]

Is there any way you can use traditional 5 pin MIDI to connect your synths to your computer? I use an ancient MOTU MIDI Timepiece AVUSB to do the deed; MOTU has more modern 8 port MIDI interfaces available. This would at least cut down on the USB usage.

[Delta Music Belgium]

I already use a Digidesign MIDI I/0 with 10 MIDI ports, but only for synths that have no USB.

As a matter of fact, switching all my synths off + disconnecting the Digidesign MIDI I/O does not make any difference at all for the keyboards and mice, the problem remains.

And when I switch to 10.9.5 all is fine, all keyboards, mice and synths are present and working.

Btw, I was able to get 2 keyboards and mice working, but I do not know why. I will keep experimenting...

[musicman691]

Originally Posted by Delta Music Belgium

I already use a Digidesign MIDI I/0 with 10 MIDI ports, but only for synths that have no USB.

As a matter of fact, switching all my synths off + disconnecting the Digidesign MIDI I/O does not make any difference at all for the keyboards and mice, the problem remains.

And when I switch to 10.9.5 all is fine, all keyboards, mice and synths are present and working.

Btw, I was able to get 2 keyboards and mice working, but I do not know why. I will keep experimenting...

Okay - but do those other synths that have USB also have 5 pin MIDI ports? If they do then use that instead of the USB bus. You may be overloading the USB bus. Most systems that have both USB and traditional 5 pin MIDI in the mix don't work very well from what I've experienced.

Just because your system works in Mavericks doesn't guarantee it'll work in Sierra. Is there any real reason you're running Sierra?