How much SpecInt do I need

Does anyone know if there is a way to determine how much power (In specInt preferably) is needed in order to support interactive (client/server) use of Oracle on an UNIX Server in a client/server environment ?

In particular, I would like to have an estimate of how much specInts/user is needed, considering a medium load on the system. What is a medium load anyway ?

Oracle gives statictics as to how much disk space or memory you need, but they give no hint on the number and/or kind of CPU that should be used in order to give reasonable performance...

Would such statistics be meaningful ? We would like to prove that the server "X" (Where X=model) can handle the job, considering that it has Y SpecInts and that there will be z users on that system.

I know there are a lot of factors that could invalidate such claims, but spec rates do not already demonstrate "real" life, so I figured that maybe such stats exists.

                                Thanks