Bremermann's Limit

Bremermann's Limit defines an upper bound on the rate at which symbols can be processed by matter.
From Einstein's (E = mc²) and Planck's (E = h f) equations Hans J. Bremermann derived that symbols can be processed at speeds not exceeding the limit of 10⁴⁷ bits/gram/second. In this way Bremermann's Limit describes a relation among matter, energy and information at the atomic Level.

Reference:
Umpleby, S. A. (2004). Physical Relationships among Matter, Energy and Information. In: Cybernetics and Systems 2004. R. Trappl (Ed). Vienna, Austrian Society for Cybernetic Studies. 1: 124-6.