Calculated pi with 487 billion digits by diskized GMP

[cents2823 at yahoo.co.jp]

> ----- Original Message -----
> 
> From: "Torbjörn Granlund" <tg at gmplib.org>
> To: "cents2823 at yahoo.co.jp" <cents2823 at yahoo.co.jp>
> Cc: "gmp-discuss at gmplib.org" <gmp-discuss at gmplib.org>
> Date: 2023/09/01 金 16:12
> Subject: Re: Calculated pi with 487 billion digits by diskized GMP
> 
> 
> cents2823 at yahoo.co.jp writes:
> 
>   I am making a program to calculate pi with gmp and Chudnovsky Algorithm. 
> 
>   If the number of digits to calculate pi increases,
>   it takes using swap and takes a lot of time(*1) to calculate.
> 
>   So I diskized(*2) some functions of gmp and calculated pi 487 billion digits.
>   It took about 10 days to calculate.
> 
>   I also calculated pi with y-cruncher and checked the result of a match.
> 
>   On the same PC, y-cruncher can calculate 1 trillion digits of pi in 32 hours. 
> 
>   Why so fast!
> 
> Or, put differently, why is GMP slow for truly huge operands?
> 
> The answer is that we haven't written great multiplication code for the
> largest operands.  We made some work in that area some years ago, but it
> never made it into GMP.

Thank you for your comment.
What is the algorithm name and multiplication performance?

S.Tsukamoto

> 
> Special purpose Pi calculation programs are tailor made for huge
> operands, of course.
> 
> -- 
> Torbjörn
> Please encrypt, key id 0xC8601622