
General Purpose Factoring Records
Below is a chart of general purpose factoring records going back to 1990.
By "general purpose", we mean a factoring algorithms whose running
time is dependent upon only the size of the number being factored
(i.e. not on the size of the prime factors or any particular form
of the number).
Sieving is typically the dominant factorization run time
in practice.
All sieving times below are approximate.
Early versions of factoring records estimated time in MIPS years,
which is the number of years it would take a computer that operates
at one million instructions per second to factor the number.
More recently, almost everybody uses Pentiums or AMDs. Thus, we
scale some timings to Pentium 1GHz CPU years: the number of years it
would take a 1GHz Pentium (or AMD) to complete sieving.
number

digits

date completed

sieving time

algorithm

C116  116  1990  275 MIPS years  mpqs 
RSA120  120  June, 1993  830 MIPS years  mpqs 
RSA129  129  April, 1994  5000 MIPS years  mpqs 
RSA130  130  April, 1996  1000 MIPS years  gnfs 
RSA140  140  February, 1999  2000 MIPS years  gnfs 
RSA155  155  August, 1999  8000 MIPS years  gnfs 
C158  158  January, 2002  3.4 Pentium 1GHz CPU years  gnfs 
RSA160  160  March, 2003  2.7 Pentium 1GHz CPU years  gnfs 
RSA576  174  December, 2003  13.2 Pentium 1GHz CPU years  gnfs 
C176  176  May, 2005  48.6 Pentium 1GHz CPU years  gnfs 
RSA200  200  May, 2005  121 Pentium 1GHz CPU years [*]  gnfs 
RSA768  232  Dec, 2009  3,300 Opteron 1GHz CPU years [**]  gnfs 
[*] In regard to RSA200, Thorsten Kleinjung writes:
we spend 25% of the total time for the matrix step.
If one considers the total time we spent about 170 CPU years.
[**] In regard to RSA768, they sieved twice as much as needed in order
to make the matrix more manageable. The matrix time took about one tenth of the
sieving time. The total time for the factorization was estimated to be about
4,400 Opteron 1GHz years.
For more factorization results, please see
the Factorization Announcements
page or
Paul Zimmermann's Factor Records page.
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