PI news by |
20th
September 1999, Adding Info. 4th October 1999
Dear folks, our latest record was established as the followings:
Declared record: 206,158,430,000 decimal digits Two independent calculation based on two different algorithms generated 206,158,430,208 (=3*2^36) decimal digits of pi and comparison of two generated sequences matched up to 206,158,430,163 decimal digits, e.g., 45 decimal digits difference. Then we are declaring 206,158,430,000 decimal digits as the new world record. |
Optimized
Main program run: |
Optimized
Verification program run: |
Frequency distribution for pi up to 200,000,000,000 decimal places: |
Frequency distribution for 1/pi up to 200,000,000,000 decimal places: |
||||||||||||||||||||||||
|
|
Some of interesting digits sequences of pi: 01234567890 : from
53,217,681,704-th of pi 432109876543 : from
149,589,314,822-th of pi |
Some of interesting digits sequences of 1/pi: 01234567890 : from
66,787,942,929-th of 1/pi 234567890123 : from
100,850,401,743-th of 1/pi |
Programs are consisted of two sets of routines, e.g. calculation routines and message passing routines. Calculation routines were written by Dr. Daisuke TAKAHASHI, a Research Associate at our Centre and rather speed sensitive message passing routines were written by myself. Calculation routines used were more optimized than these used for the 51.5 billion record establishment.
For establishing this new record, high speed message passing routines were seriously used for both of programs, e.g. main program and verification program. CPU used was HITACHI SR8000 at the Information Technology Center, Computer Centre Division (old Computer Centre,) University of Tokyo. Full of the total CPU, e.g. 128PE's (theoretical peak processing speed for the single PE is eight billion floating operations per second. One trillion floating point operations per second for all PE's), were definitely used as single job and parallel processing for both of programs run.
Yasumasa KANADA |
|