Sorry, by "these quantities" I meant "at computer-chip quantities" in general; gold we pretty much use by area, and not much of that, either. The numbers I gave were purposely quite generous for volume. After all, I did say they were probably 3 or 4 orders of magnitude too generous. Per reitzensteinm's post, looks like you can recover another 1.5 or so out of my chip-height estimate, too.