PiFast: Meaning (information, definition, explanation, facts)

PiFast is presently the fastest program for Microsoft Windows to compute digits of the mathematical constant π. On an Athlon XP 2000+ underclocked to 1620 MHz, it computes one million digits in 4.75 seconds. It can also compute other irrational numbers like e and √2. PiFast can work at lesser efficiency with very little memory (down to a few tens of megabytes to compute well over a billion (10⁹) digits).

This closed source freeware tool is a popular benchmark in the overclocking community, and has been used to compute over 20 billion (2×10¹⁰) digits of π (the present record on a desktop computer).