Why does Apple recommend using a runloop over GCD for fetching multiple images?

Question

Is it a good idea to load images (1 block each) through Grand Central Dispatch in iOS 4.0? (for use in a UITableView)

Why is a runloop preferred by Apple, as illustrated in the WWDC video sessions 207 and 208?

Answer 1

The point being made in those videos was that Foundation networking does not integrate well with Grand Central Dispatch right now, so if you want to do Foundation-based networking a runloop is your best bet for avoiding the problems of traditional threads. However, in Session 206 - "Introducing Blocks and Grand Central Dispatch on iPhone", you'll see that they show an example of how to use GCD for just this purpose.

Me, I prefer GCD because of the elegance of the code and because (as they state in those videos) it is the way of the future.

Answer 2

I haven't watched those videos yet, but here is what Chris Hanson (Apple Engineer) says about GCD vs NSOperation

Always use the highest-level abstraction available to you, and drop down to lower-level abstractions when measurement shows that they are needed.

In other words, you should be using NSOperations to do asynchronous processing (such as loading images for a table view) unless you have a good and necessary reason to go for GCD.