I am NOT very informed about server tweaking, so please add a pinch of salt as appropriate... But aren't there two related issues to consider? Assuming a simpli

I am NOT very informed about server tweaking, so please add a pinch of salt as appropriate... But aren't there two related issues to consider? Assuming a simplistic two-tier architecture consisting of a UI/domain logic server (in PHP) backed by a database, the first question is whether the speed of the PHP bit affects the total load the server can handle. Presumably if it is idling waiting for the database, you could handle some more connections and need to work on optimizing your database until you reach a sort of equilibrium where both are maxed out. The second issue is latency. Even if it spends time waiting for the database, the amount of time processing each request affects the amount of time a client waits for a response. Even if the database is the limiting factor on the number of simultaneous requests that can be handled, you may still want to increase the speed of handling each request to make the UI snappier. Am I whistling in the dark here?