swapfile query

Hello list,

(freebsd-current is r317212 on this machine)

I have a machine with 128GB RAM. When 12-current was installed, for some
reason the swap partition was set to 4GB. I see sometimes via top and
also via daily status reports that sometimes the machine runs out of
swap. It doesn't crash the machine though.

I know how to add more swap with a swapfile. My questions are:

1. should I make more than one swapfile, say 4x32GB or will it be ok
with one 128GB swapfile?

2. will the 4GB already there as swap play nice with a swapfile, or
multiple swapfiles? Or should I deactivate the 4GB swap partition first?

3. should total swap be 1x 2x or some other multiple of RAM these days?

FreeBSD and the swap partition reside on the same SSD. The swapfiles, if
created, will reside on this SSD.

thanks,
-- 
J.