Dissection of the Apple A4

Not at all. This thing runs a slim Unix-based embedded OS. Why would it need more memory?

I use a netbook with 1.5 gigs and a non-slim Unix-like OS with X and Gnome on top of it and it rarely hits swap.

No, it just asserts that because there's only one core it has to be an A8 (superscalar, no provision for SMP) not an A9 (out-of-order speculative issue superscalar, single core and 1-4 cores SMP versions).

well as far as i understand things, an arm chip is a collection of modules that perform different functions. so it could have described which modules are present (you'd need to grind horizontal sections).

also, although i guess more difficult, it could perhaps have tried to look at what makes this chip different. arm chips seem to be pretty common; what was so special about this that apple needed to do their own?

The consumables involved in stripping off metal and oxide layers have a negligible price point. Most of the cost is engineer time, though how much depends on what equipment/techniques are used (liquid chemistry, manual polishing, plasma processing, etc.).

This isn't the case with all circuit forensics techniques: once you start loading parts into more expensive equipment (even electron microscopes) you're paying for tool time to offset training and tool value depreciation.

I know that's not really quantifying things, but that's something you'd have to get from the lab that actually performed the work.

EDIT: if it helps, the actual process of removing a metal layer and an oxide layer varies with the process, but would generally take under an hour (and usually well under). There exist techniques to skip all that and go straight to silicon significantly faster, though as these are all destructive processes, you lose the ability to go back and see what was there before.

I would not be surprised if Chipworks wasn't paid for this article. It might have been a PR project. At work we sometime do this to get our company in the news.