Google does not use very large or even large machines for most of their fleet. You can quickly see in the paper this is for 1, 2, and 4 GB RAM machines (in 2006-2008).
These were state of the art 13 years ago. It’s not safe to extrapolate from this paper that they aren’t using servers having significantly more memory today. Thirteen years is more than 2 full depreciation intervals.
