This is a very nice observation that I've found in the dancing links paper : My trusty old SPARCstation 2 computer, vintage 1992, is able to perform approxi- m

This is a very nice observation that I've found in the dancing links paper : My trusty old SPARCstation 2 computer, vintage 1992, is able to perform approxi- mately 0.39 mega-updates per second when working on large problems and maintaining the S fields. The 120 MHz Pentium I computer that Stanford computer science faculty were given in 1996 did 1.21 mega-updates per second, and my new 500 MHz Pentium III does 5.94. Thus the running time decreases as technology advances; but it remains essentially proportional to the number of updates, which is the number of times the links do their dance. Therefore I prefer to measure the performance of algorithm DLX by counting the number of updates, not by counting the number of elapsed seconds.