Ask Donald Becker
This is a "needs no introduction" introduction, because Donald Becker is one of the people who has been most influential in making GNU/Linux a usable operating system, and is also one of the "fathers" of Beowulf and commodity supercomputing clusters in general. Usual Slashdot interview rules apply, plus a special one for this interview only: "What if we made a Beowulf cluster of these?" is not an appropriate question.
If I recall, the definition of a Beowulf cluster does not specify Linux specifically, only a free operating system.
Look it up
Beer wants to be free