hw info

Motherboard:
dmidecode -t 2

Memory
dmidecode -t 17

Hard drive:
hdparm -I /dev/sda
lshw -class disk
fdisk -l
smartctl -i /dev/sdb
udevadm info --query=all --name=/dev/sda | grep ID_SERIAL

CPU:
cat /proc/cpuinfo

Physical CPU count
cat /proc/cpuinfo | grep "physical id" | sort | uniq | wc -l
How many cores?
cat /proc/cpuinfo | grep "cpu cores" | uniq

Network card
lspci | egrep -i --color 'network|ethernet'

HW Raid controller
lspci -vv | grep -i raid