Background threads consuming 100% CPU on iPhone 3GS causes latent main thread

Question

In my application I am executing 10 asynchronous NSURLConnections within an NSOperationQueue as NSInvocationOperations. In order to prevent each operation from returning be

Answer 1

In practice you simply cannot have more than two or three background network threads and have the UI stay fully responsive.

Optimize for user responsiveness, it's the only thing a user really notices. Or (and I really hate to say this) add a "Turbo" button to your app that puts up a non-interactive modal dialog and increases concurrent operations to 10 while it is up.