The CHM has got from IBM an intermediate assembly unit from one of IBM’s “<a href=http://en.wikipedia.org/wiki/Blue_Gene>Blue Gene</a>”s.
Its aquisition number (or “catalog number”) is <a href=http://www.computerhistory.org/collections/catalog/102740911>102740911</a>.
It holds 36 computer chips which I presume each hold one or several Power processors.
The volume for these 36 chips is 0.0195 m<sup>3</sup>.
Two of its dimensions appear to be designed for close packaging.
The 3rd dimension seems to be designed to carry a substantial cooling wind.