Normally, I try not to mess with
/etc/fstab or other config files unless absolutely necessary to get something working... Just accept the defaults the installer gives you, and in 5 minutes you can have a brand-new, bootable FreeBSD system that you can build on.
Tuning an OS for best performance is a bit of an art. Normally, you first gotta have some visible reason to mess with sysctls,
/etc/fstab, and the like. Otherwise, it may be a wiser decision to just accept the defaults, because they're likely to work fine. If default setup doesn't work for some reason, and a solution involves messing with
sysctl
s, then by all means, go ahead, do your homework, and then adjust the
sysctl
s until your problem is solved. Just make sure you have backups and a way to undo a mistake. Oh, and take good notes on what you did.
Pushing buttons and adjusting settings at random, just because you can - that's not a great approach to learning FreeBSD.
BTW, when you reinstall FreeBSD, I'd suggest going with ZFS, and accept the defaults - that includes just 2 GB of swap. Dunno why you'd need more - Linux wisdom dictates that more swap is generally better, but on FreeBSD, that idea is turned completely on its head. And I'm quite happy with the results I got - I have a couple rigs with 32 GB RAM, and they're capable of compiling even the big stuff like
www/firefox... And yes, both rigs have just 2 GB of swap...