Site Performance Issues? Research First.

So CPU is spiked and it's time to upgrade your web server to a new one. Or is it really a problem with CPU?
In many cases finding what the particular performance issue is with a website can be complicated. There can be several layers to a web application. For example:

Http request comes in for ASP.NET web page.

Logic is ran, checks for cached file on the disk.

If there is no cache, it will then go over the network to make a request to SQL server.
SQL Server will check the database on disk for the data and return back through the network.
The ASP.NET web page gets a response back from SQL, writes to a local cache, and responds back to the requesting client.

It even gets more complex in high availability environments. At that point you need to isolate any load balanced servers and  individually check each one to see if the problem isn't with the overall application, but one of the servers.
Now throw in a web service layer, objects that connect to