[LAD] Multiple JACK servers connected in one host?

[Paul Davis]

On Fri, Mar 11, 2016 at 11:53 AM, Jonathan Brickman <jeb at ponderworthy.com>
wrote:

>
> the "engines" i'm referring to are your many multiple clients (19 or so).
>
> OK, I think I see what you are referring to: the switching nature of the
> client list, where the JACK server has to switch between.  And this is
> entirely why it helps to run multiple JACK servers on multiple
> motherboards, and why it will help to run multiple JACK servers on my box,
> because the client list reduces tremendously per JACK server
>

No, it will not. The entire graph is driven by a single time/clock source
(your audio interface).

>From the moment that clock ticks (generally via an interrupt to the CPU)
until it ticks again, the entire JACK graph (regardless of how clients
and/or network-connected other JACK servers are involved) MUST complete
execution.

If you use sequential execution, then everything will happen on 1 core. If
the dataflow is parallel (which your case does include, partially) then
this may waste computational resources that could be used to drop the DSP
load.

So you can parallelize it to the extent possible, which JACK2 already does.
In your case, there are times when it could be using up to

But you get NOTHING from using additional JACK servers except for more time
spent on context switches and communication overhead. The clients are
already being parallelized as much as they can be.

You are not maximising the CPU resources you have available because you
don't have a fully parallelizable data flow. There's no way that using
multiple computers, multiple JACK servers or anything can get around the
fact that clients D, E and F cannot be executed until clients A, B and C
are done. This happens multiple times in your data flow.
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