What can I expect?

Generally speaking, If I were to have a setup that included the following: a CPU, and Northbridge cooler, along with a pump, resevoir, and radiator with fan. How much would it offset my system temps temps?

there was a thread asking the same thing... search a little and you should find it...

And if you want a good answer, you should give more detail (your setup, and what watercooling parts you plan on using)... just my 2 cents though