Swap on SD or on usb flash drive for rpi2?

[bob prohaska]

Hi all,

For some reason my rpi2 insists on having a token amount of swap.
It's running FreeBSD rpi2 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r285428: Sun Jun 14 02:20:56 UTC 2015     bob at rpi2:/usr/obj/usr/src/sys/RPI2  arm
(please disregard the date, the system built itself today, July 13 2015)

When running a buildworld cycle it uses about 68 MB of swap. It
happens that the md filesystems use close to the same amount of
space. By any chance could the need for swap be eliminated if the
memory filesystems were replaced by physical partitions on the
SD card or a usb flash device?

If physical swap _is_ mandatory is there significant advantage to
placing it on a device separate from /, as with mechanical disks? 

Thanks for reading and any guidance,

bob prohaska