What are your computer's specs? (CPU, RAM, hard disk speed and size, etc)
What version of PT3 do you have?
How big is your database?
How many tables do you play?
Which version of PostgreSQL do you have? (see Database > Database Management)
If it doesn't say 100% for all sections in the status bar of PT3 please run Database > Housekeeping - that is one of the most likely issues.
Check the
FAQ: PT3 HUD for optimization tips.