title: iPhone: Performances Differences Between NSURLRequestCachePolicy Settings
body: <p>When using <a href="http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/Foundation/Classes/NSURLRequest_Class/Reference/Reference.html#//apple_ref/doc/c_ref/NSURLRequestCachePolicy" rel="noreferrer">NSURLRequest</a> on the iPhone, what are the real world performance differences between the various <a href="http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/Foundation/Classes/NSURLRequest_Class/Reference/Reference.html#//apple_ref/doc/c_ref/NSURLRequestCachePolicy" rel="noreferrer">NSURLRequestCachePolicy</a> settings? I am specifically interested in the cache policy's effect on the the user's perception of the speed at which UIWebView pages display.</p>
  <p>I have been using the default <code>NSURLRequestCachePolicy</code> but I think that perhaps NSURLRequestReloadRevalidatingCacheData could be best for most cases especially when going back to a previous page.</p>
  <p>If you've used various cache policies under real-world conditions, which policy proved optimum in a particular circumstance?  What policy provides the best overall performance over the three different types of iPhone connections, wi-fi, 3G and Edge? Does the cache policy even have any significant effect on the user's perception of page loading speed or should I be looking elsewhere to optimize UIWebView's display time?</p>
  <h2>Update:</h2>
  <p>There seems to be a consensus that UIWebView appears to ignore the cache settings on any NSURLRequest given it. I do not have complete confidence that this is the final answer but barring the time to do some extensive testing, I cannot gainsay it. Therefore, I am accepting the highest rated answer. However, I would advise that you take the answers with a grain of salt if the matter is of importance to your project. -- TechZen.</p>