Time to boot linux depends on what services you start on booting and configuration of the PC. Better CPU and Memory always improve boot speed.
By default linux have many services that can turn off. For example, desktop computer won’t need mysql or apache started. auditd – shutdown it as it is not used by most, there are many similar unused services running on your desktop.
chkconfig --list
will show list of all services and its status on init levels.
Bootchart is a software that shows time taken in boot process
