> Is patch generally applied to resources I the multiple gigabyte range, very possibly with the original resource size exceeding the total amount of installed RAM in the system?

That's where bundling all your data files into a single large archive bites you in the butt. Individual files the game uses ain't gonna be that large.

The reason why games have such large files is that the fastest way of loading a game is to do a serial read of the data, ergo the large files.

Sure, but now we're talking about game developers making choices based on distribution and patching instead of what they would likely view as more important considerations, such as performance and ease of development use.

Perhaps they could break stuff apart prior to shipping, but I imagine that could cause a lot of QA headaches as sure it should all work perfectly fine if a solution is used that transparently supports both combined and split formats, but who wants to bet the ship date of a multi-hundred million dollar project on that?

Welcome to the launch of the Xbox One.