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These days even a desktop computer is capable of some extreme number crunching

Getting a lot out of a little is one of the most fascinating forms of enthusiasm in the tech community.  Whether it's squeezing Windows 7 onto a Pentium II dinosaur, or making a homebrew SNES handheld, such endeavors are truly intriguing.

Perhaps the latest and greatest wonder of hardware overachievement is the story of French native Fabrice Bellard, who now holds the world record in PI calculation.  He calculated Pi to 2.7 trillion decimal digits, surpassing mark of 2.5 trillion digits set in August by the T2K Open Supercomputer (which at the time was the 47th most powerful supercomputer in the world).

So what's so impressive about Mr. Bellard's feat, aside from its basic technical merits?  He accomplished the number crunching, not on a supercomputer, but on a Nehalem-powered desktop.

His machine featured a Core i7 CPU running at 2.93 GHz, 6 GB of RAM, and five 1.5 Terabyte Seagate Barracuda 7200.11 model hard drives (for a total of 7.5 TB).  The system ran the 64-bit Red Hat Fedora 10 distribution as its primary OS and used software RAID-0 and the ext4 file system.

The result takes up 1137 GB of storage and is (partially) available here.  The computation took 103 days of computing time for the modest desktop. 

The only time when Mr. Bellard had to enlist the help of other computers was during the verification.  In order to avoid being displaced from the top spot while the desktop chugged on the results (that would have taken an additional 13 days), he instead used a network of nine computers to verify the results in a shorter timespan.

In order to calculate Pi, Mr. Bellard used a software algorithm based on the well known Chudnovsky formula and verified the resulting calculations by the Bailey-Borwein-Plouffe algorithm which directly gives the n'th hexadecimal digits of Pi.  Checksums were used to detect errors.

The more optimized Pi algorithm based on the Chudnovsky formula that Mr. Bellard uses is the fastest current way to calculate Pi and has been renamed Bellard's formula in his honor.  Mr. Bellard is perhaps most famous for writing the tiny c compiler (tcc), a popular lightweight compiler in the Linux community.



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RE: Vive la France
By Hieyeck on 1/6/2010 10:12:05 AM , Rating: 5
A woman covered in pie is never an error.

Sexism be damned, I couldn't resist.


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