# Super PI

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**Super PI** is a computer program that calculates pi to a specified number of digits after the decimal point - up to a maximum of 32 million. It uses Gauss-Legendre algorithm and is a Windows port of the program used by Yasumasa Kanada in 1995 to compute Pi to 2^{32} digits.

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## [edit] Significance

Super Pi is used by many overclockers to test the performance and stability of their computers. In the overclocking community, the standard program provides a benchmark for enthusiasts to compare "world record" pi calculation times and demonstrate their overclocking abilities. The program can also be used to test the stability of a certain overclock speed. If a computer is able to calculate PI to the 32 millionth place after the decimal without mistake, it is considered to be moderately stable in terms of RAM and CPU. However, longer tests with other CPU/RAM intensive calculation programs will run for hours instead of minutes and may better stress system stability. While Super Pi is not the fastest program for calculating Pi (see software for calculating π for faster alternatives), it remains very popular in the hardware and overclocking communities.

## [edit] Credibility concerns

The competitive nature of achieving the best Super Pi calculation times led to fraudulent SuperPI results, reporting calculation times faster than normal. Attempts to counter the fraudulent results resulted in a modified version of Super Pi, with a checksum to validate the results.^{[1]} However, other methods exist of producing inaccurate or fake time results, raising questions about the program's future as an overclocking benchmark.

## [edit] The Future

Super PI was single threaded, so its relevance as a measure of performance in the current era of multi-core processors was diminishing quickly. As the calculation times became faster and faster, Super PI was also becoming a rather poor stability test due to the fact that a stability test needs to run long enough to properly stress test the hardware. Many users were moving to Orthos or OCCT for their stability testing since those are multithreaded programs.

Intel and AMD have introduced new instructions to the x86 instruction set. The most obvious enhancement was the x86-64 extension, but numerous instruction set extensions (e.g. SSE) have also been added.