Hi Chris,
there is a reason to store /tmp on the disk: space needed within it. Some
tasks use much of it, like building OpenOffice (I tried it in 2010 in
ArchLinux and it stopped when filled up my 8GB /tmp partition) or editing big
audio/doing many tasks into a single Audacity session (Audacity comes
configured by default to use /tmp for temporary files; it's possible to
change that). There is no swap for tmpfs.
However, /tmp is much faster on RAM than on disk. I think it's better to
close Audacity and open it again when needed than to wait for minutes to have
an audio safety copy. And I never tried to build OpenOffice/LibreOffice
again, nor do I build anymore every package in my system.
Also, as tmpfs, it's for sure that /tmp will be cleaned on system halt; I
don't know if the default is to clean it on boot, but I prefer in halt.
Probably this cleaning-up on halt enhances privacy compared to it on boot.
Aaaand putting it in RAM, where it's size is limited and dynamically managed,
saves disk space for other things.
