# grep memory /var/run/dmesg.boot
real memory = 1610612736 (1536 MB)
avail memory = 1524379648 (1453 MB)
% sysctl hw | egrep 'hw.(phys|user|real)'
hw.physmem: 1575231488
hw.usermem: 1237983232
hw.realmem: 1610612736
% sysctl hw.physmem
hw.physmem: 1575231488