General Tuning for Unarchived Data

We're currently on PeopleTools 8.53 and applications 9.1, but will be upgrading to the latest versions this summer.

We've noticed that in a lot of areas where there's large amounts of data (e.g., PeopleSoft HR, Review Employee Self Service Paycheck) transactions begin to time out (e.g., trying to access an employee with 400+ checks.

While the best solution is to archive the data, is there an interim solution or anything that can be done to tune/throw hardware at the problem? Is there something that can be done configuring the application server?

I don't think it's a database issue, since performing similar raw queries w/ a SQL tool return the data pretty quickly.