All perfomance related calculations must also be conventionally done, like TOC (if relevant), TOD, actual weights and respective speeds.
Regarding this topic I recently had an FMS unable to give any performance outputs on a 737 classic: not a too big deal, but workload, especially on really short sectors, might slightly increase.
p.s. my first post (tech-log, I am pretty brave!) but a long-time reader. Hello everybody
