Work with portal system administrators and portal developers to set the portal performance objectives based on the projected requirements of your portal. Objectives include the number of users, the number of concurrent users at peak load time and their usage pattern in accessing Portal Server.
You need to determine these two factors:
Are you tuning for portal applications rapid response?
Are you tuning for a large number of user concurrency?
As the number of users concurrently connected to the portal increase, the response time decreases given the same hardware and same set of parameters. Hence, gather information about the level of usage expected on your Portal Server, the anticipated number of concurrent users at any given time, the number of Portal Desktop activity requests, the amount of portal channel usage, acceptable response time for the end-user which is determined by your organization, and an optimal hardware configuration to meet the criteria.