Steps for performance tuning of a sql server


I just wanted steps /how to troubleshoot sql server from perfmonace point of view or which is particualr query perfmoing slowly

I mean how to decide whather its hardware problem (like more cpu , ram or disk io system required ) if it hardware then how to suggest to increase the same or better

If its sw i mean with logical i.e query then how to pin-point what exacts issue is

How people go here with PT .What steps one takes before decciding whether its issue is in query ot in hardware.

I know above knowledge comes from expernice and learning but if get basic ideas/steps


Here are some important steps for performance tuning in SQL Server: