you've got no headroom left for load spikes! but this sort of question obscures the reality. are you asking this in the context of a machine which is running

you've got no headroom left for load spikes! but this sort of question obscures the reality. are you asking this in the context of a machine which is running slowly? are the clients which are querying the DBMS acting differently? has there recently been a change to the application which might have brought this about? have the marketing department started an advertising campaign without telling you?