There was an interesting thread
"jack dsp load calculation" on
http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org,
opened by Robin on Wed, 23 Dec 2015 16:35:33 +0100.
Unfortunately it's not available in the archive:
http://lists.jackaudio.org/private.cgi/jack-devel-jackaudio.org/2015-Decemb…
:(.