The Intel microprocessor inside most of those PCs: up eight-fold (in logic gates) and five- to tenfold (in speed) since 1989.

FORBES: Rational Exuberance

Of course, they haven't built a living genetic PC just yet, but to speed up its development, the team has contributed all the transcriptor-based logic gates to the public domain.

ENGADGET

In what appears to be an early proof-of-concept for DNA computing, scientists at Columbia University and the University of New Mexico have created a basic computer, called the MAYA-II, which has a molecular array of YES and AND logic gates made up of 100 DNA circuits.

ENGADGET: Meet MAYA-II, the new DNA computer that can play Tic-Tac-Toe

As is his style in product reviews, Gates pressed Allard, challenging the logic of the approach.

FORBES: As iPad Launched, Bill Gates Helped Kill Microsoft's Own Tablet To Save Windows

Gates loves the challenge of racing down a logic tree of decisions and potential outcomes over a range of business scenarios.

FORBES: Digital rules