Greek mathematician Archimedes was the first one to use geometric methods to calculate the value Pi(π) to an accuracy of more than two decimal places. After that contributions from other mathematicians like Sir Isaac Newton and Srinivas Ramanujan made it possible to calculate the value of Pi to millions of decimal places. In 1987, Chudnovsky brothers gave the method that made it possible to calculate the value of Pi to trillions of decimal places. It is this formula given by Chudnovsky brothers that is used by a program called y-cruncher to calculate the value of Pi to 2.5 trillion number of decimal places.
Since calculations by y-cruncher requires heavy use of the system memory, it can be used to stress-test your installed RAM too. This program is available for both Windows and Linux. You can download the program and double-click on y-cruncher.exe to launch it. In the good old fashioned console program style, it allows you to pick an option from the list – benchmark Pi, component stress tester, custom compute, digit extractor, digit viewer and more.
The first option – Benchmark Pi starts the calculation of Pi in the RAM and therefore is used to test your RAM. But you are allowed to pick the number of decimal places for Pi that you wish to compute. You can choose from 25,000,000 to 2,500,000,000,000 number of decimal places. Depending on the length of Pi value, it may take from 222 megabytes to 11.5 terabytes of your RAM.
The time taken for computation could be shorter or longer depending on the length of Pi. For only 25,000,000 digits, it will finish only in a few seconds. But for the trillion digits, it may take more than a day. In the end, it does not display the complete computed value of Pi but instead only the last hundred digits.
You can download y-cruncher from http://www.numberworld.org/y-cruncher/.