============================= Billion digit pi on a desktop ============================= On May 31, 1999, Dominique Delande successfully computed 1,073,741,824 digits (of which 1,073,741,686 were correct). This is the largest number of digits of pi ever computed on a desktop computer. The system was a Pentium-II Xeon running at 450mhz, with 1g of memory and running Linux. (Due to the nature of my program, only 512m was actually used for the NTT.) The run took 758,058 seconds total, with (according to Linux) 421,633 seconds being consumed by the computation itself, with the remainder being used by the OS and disk I/O. He used v2.3 of my program with the gcc586 module, 8 prime, and disk numbers. He used the sqrt(3) Salamin formula. The use of the gcc586 required one level of FractalMul. Doing this large of pi run really pushes your system, and my program. For example, file sizes are about as large as what many OS's allow. In fact, the save file for the 1g run was 3g, which is _larger_ than what Linux or DOS/Win98 allows! That means that you can *NOT* save the progress. You have to do the full run, without interruptions! (Those routines could be modified. They are in common/bigint.c. But I don't want to do that because I want to keep this distribution as close to the 'v2.3' it is. I'm not ready to release a v2.4 yet.) Also, the gcc586 has a multiplication limit of 256m digit numbers. Since the AGM only multiplies half sized numbers, that means it needs to multiply 512m digit numbers. The gcc586 has to use one level of the FractalMul. The other versions of the NTT32 have a 1g limit, so they wouldn't need the FractalMul. Below is an excerpt of the last few thousand digits of the pi run. Just in case you try it yourself. 0961364881 2408629617 3173850030 0158229966 1490728159 9318711789 0382103610 0572055737 9131195220 5180109290 4065977001 5226314100 3261394101 8431436152 4937856633 2773267866 0843966116 7424297999 8629692155 6003115656 2265096256 4809134840 2871215787 3436870102 2131334883 4913312953 1268724186 8362663830 9455400930 3596096502 3021851064 0641459568 5385215462 7125007019 2294670694 8509868159 5830711007 9639445959 0063815160 8733609363 2705143208 3644574281 8000630130 7920334483 0327890683 8675846338 1850202091 9141798471 2952746050 4530776848 1027261430 0214520936 0699068956 9063255786 1177836551 7819065005 3239340766 1566890694 6652291675 2282150857 0272638104 2503346529 0703210022 3749737101 8219963803 5919348161 9866685093 5059299351 3172044515 8067238543 5056041041 1915799244 4710932291 5638990410 9076758122 9488820306 9380336081 8459762629 7202951577 2197613892 2944170872 9661774908 0103441133 4062350612 2766969625 3565876402 0927556475 5947018025 0886680421 4733008738 3895468354 3383720083 9913767283 4424394444 4028968344 6335705875 1279944509 2230387995 7901254418 3959995325 6018769253 7058302884 7192464652 9509098067 6457364230 2688184131 1486112057 5871673712 2250198875 2258885388 1606881075 3420337076 7507310779 9922772123 0423922854 0005053906 3823124866 9683077316 1838425520 7086543627 7755347255 0085746116 2443554812 7402219689 7712390340 2239655563 9236844741 3677387095 6590694805 4597061943 5265566838 0629232147 9185066886 6404389435 7936957275 8586133116 2000452361 0364191678 7755091373 8402134212 6803354684 9705428757 4782318544 2339132775 8587644972 4461764157 5997179191 9509695013 1321372705 0401973377 5431163090 7644314318 7894414039 9374825151 2350686669 1315258320 4683679026 1654214913 1557665608 6120077780 9502250438 2719850488 8388450319 4617756423 1422391547 8041878202 1508018438 0696051751 4339959546 6432696834 0773924643 3380871003 1279321612 7896758930 6726664688 7758486377 6970935173 4627194266 6842383136 5293922631 9363128132 4640140784 9316795508 4214490948 6636871447 0062254660 1902888726 5783048232 3528210233 6476033028 9067286443 6293450232 4763798057 5446902246 8404016065 2736258229 0073721500 8555985825 8824554483 6641445138 2964265471 6481643735 6827298829 9000391522 9459344333 1620724647 5607372455 0286833857 0538282954 3439094583 7522903566 6784873793 3325134979 9405683731 1835071837 0151833367 3566280477 6506424654 7345545499 4293449348 6968990044 8987395937 3408796060 5192054375 2853647484 0072213278 5933924853 4859932848 5932498717 8673989750 4925452491 6903269538 3271477465 0439998652 0434434170 7904695488 1172725221 3789862348 3822822721 1654529439 1616837374 6298350728 8398165246 1278875381 5306175514 4590906819 0362896137 8319993708 1044307371 4163891553 1451322989 0055850993 9872253326 4915621234 3017183736 8931844878 5900485186 6688390474 2756646731 2281784066 4862946034 6666674356 9602873913 4395467543 7984689788 7708900712 0255039289 6161841508 3092054335 7339829704 2952550660 7215349001 2248585208 9498588207 5912231871 0314801619 6903062303 7213421117 3023111759 9660831013 6759154145 5727787324 6190699827 0659868940 2395669411 2407797584 9710694717 7340887489 6193875015 0001939744 3544357012 3358216580 2636130855 4080747351 3196820047 8798550160 0589130178 1291099851 2278419464 1894735831 2719334069 6698995342 9280916185 2317335986 5083212737 2364112193 2490470626 3136712719 3813013933 3899240990 1775516632 4882095223 0799242044 9319870133 7096056870 8459497589 1450651737 5349288579 7175967548 7935623711 9360774997 4822512233 0812174841 3964484787 2433072172 7827489180 7312491337 7443437578 5779873379 8739791763 8178861649 8751609581 0477142839 3846724504 6405129400 4921304361 3992479005 5291129079 9757622793 6789398965 6083242633 3692647976 5701605100 9004963674 7523688739 2806200071 1144682333 4355220522 9111054044 6482767937 1878223567 3903057078 1889447449 8215594718 8095871152 8461751957 6210971073 8267804389 3454238213 3833995305 9815794419 9585868816 3167078896 8386333470 0039314433 5955164532 3053107157 7542428018 5926562977 5008607813 8683454632 9522849757 7897537461 3611634291 9044086269 5648295458 8670764985 8535531625 2530600169 9242155421 2157181996 9374699507 2282716836 1994826186 1806057683 5611324235 2221864902 0380645030 8325366658 2812891770 4332004360 3266627722 5168418657 7363756148 4080670653 6597775345 8714581579 9934000045 4772240182 1395517870 0421258541 6808437154 9279654711 5794408984 5000971425 6448844823 5737223491 3017290855 6084562252 0056074359 7766408794 6464779131 5984941925 6421729322 1703325952 6660355672 5576555360 0346191586 6714149130 0691448523 5777343974 4344576913 7753375625 5732265672 2090560598 2525691280 4079166282 5957071853 6140633001 0465020334 6440281692 9074927845 7492668027 3735546793 1613189891 2502020620 8940919290 8785321718 8132439885 2797173490 3533304763 1642231241 1158669653 2733721363 1760996876 1864999514 8992081247 4991853255 5254578758 2903707694 3725298210 1826990232 510 Fast 1/sqrt(2) AGM computed 1073741824 digits in 758058 seconds.