title: NSOperationQueue vs GCD
body: <p>In what cases would you prefer to use <code>NSOperationQueue</code> over GCD? </p>
  
  <p>From my limited experience of these two, I take it that with <code>NSOperationQueue</code> you basically have control over how many concurrent operations there are.</p>
  
  <p>With GCD you can't do this, since you are using a queue. Except you can somehow simulate this with a multi core processor, although still I think there's no way to control it.</p>