I always look into /var/vm/, and count the swapfiles to find out if I need more RAM.
If, after regular use, there are two swapfiles (swapfile0, and swapfile1), then the Mac could use more RAM.
swapfile0 is always present, but a 2nd (or 3rd) swapfile is only created when your Mac is using diskspace for RAM. If it only appears occasionally (after playing some heavy games orso), I wouldn't bother, but if multiple swapfiles are created after normal use, then I would recommend adding extra RAM.
If, after regular use, there are two swapfiles (swapfile0, and swapfile1), then the Mac could use more RAM.
swapfile0 is always present, but a 2nd (or 3rd) swapfile is only created when your Mac is using diskspace for RAM. If it only appears occasionally (after playing some heavy games orso), I wouldn't bother, but if multiple swapfiles are created after normal use, then I would recommend adding extra RAM.